Generated banner for Zeroize Audit
Generated logo for Zeroize Audit

Zeroize Audit

Trail of BitsOfficialPublished by Trail of Bits

  • Skill
  • Review and audit
  • Security
  • CC-BY-SA-4.0
  • Low risk
  • Has scripts

From the author

Detects missing zeroization of sensitive data in source code and identifies zeroization removed by compiler optimizations, with assembly-level analysis, and control-flow verification. Use for auditing C/C++/Rust code handling secrets, keys, passwords, or other sensitive data.
— the description by Trail of Bits

AutoGineer summary

Written by AutoGineer from the skill’s own files, not by the author

zeroize-audit is a specialized security analysis tool designed to verify that sensitive data—such as cryptographic keys, passwords, and tokens—is properly wiped from memory. It goes beyond simple source-level scanning by performing assembly-level analysis and control-flow verification to detect instances where compiler optimizations, such as dead-store elimination, inadvertently remove security-critical zeroization operations. The tool produces a structured report and generates proof-of-concept programs to validate findings, providing a rigorous audit path for security-sensitive software.

What it does

  • Detects missing zeroization of sensitive data in source code.
  • Identifies zeroization operations removed by compiler optimizations using IR and assembly diffing.
  • Performs control-flow graph analysis to verify cleanup on all execution paths.
  • Generates and validates proof-of-concept programs for identified vulnerabilities.
  • Provides assembly-level analysis to detect stack retention and register spills of secrets.
  • Supports C, C++, and Rust codebases with language-specific analysis pipelines.

When to use it

  • Auditing cryptographic implementations and key management systems.
  • Reviewing authentication systems handling passwords or session tokens.
  • Analyzing codebases that process PII or sensitive credentials.
  • Verifying secure memory cleanup in security-critical software.
  • Investigating memory safety and data leakage risks in compiled binaries.

Advantages

  • Reduces false negatives by accounting for compiler-level optimization behaviors.
  • Provides actionable evidence through generated proof-of-concept programs.
  • Supports complex analysis including control-flow and assembly-level verification.
  • Automates the tedious process of manual security code review for memory wiping.
  • Integrates with existing build systems via compile_commands.json or Cargo manifests.

Usage examples

“Audit this C library for secrets left in memory.”
The agent will analyze the provided compile_commands.json, perform source and compiler-level analysis, and generate a report detailing any missing or optimized-away zeroization.
“Check that this Rust crate actually wipes its keys.”
The agent will use the Cargo manifest to perform MIR and LLVM IR analysis, identifying if sensitive data is properly cleared or if compiler optimizations have weakened the security.

Install

  1. Download the skill as a ZIP:

    https://autogineer.com/agent-skills/trailofbits/zeroize-audit/download
  2. Unzip it into the cross-client skills folder of your project:

    mkdir -p .agents/skills && unzip zeroize-audit.zip -d .agents/skills

Documentation by Trail of Bits

zeroize-audit

When to Use

  • Auditing cryptographic implementations (keys, seeds, nonces, secrets)

  • Reviewing authentication systems (passwords, tokens, session data)

  • Analyzing code that handles PII or sensitive credentials

  • Verifying secure cleanup in security-critical codebases

  • Investigating memory safety of sensitive data handling

When NOT to Use

  • General code review without security focus

  • Performance optimization (unless related to secure wiping)

  • Refactoring tasks not related to sensitive data

  • Code without identifiable secrets or sensitive values


Execution Contract

Use the agent environment's available tools for file access, shell commands, worker execution, and user input. The allowed-tools entry and role-file frontmatter are legacy host metadata; they do not define another environment's tool names or grant permissions there.

  • Resolve resources. Set baseDir to the absolute directory containing this SKILL.md. Confirm the linked input schema and orchestrator prompt exist there. {baseDir}, {workdir}, and {{input}} are notation for values the orchestrator must substitute, not environment variables or automatic host expansion. Resolve relative Markdown links against the directory of the file containing them; resolve {baseDir}/… paths against the skill directory. Pass resolved paths to workers and shell commands.

  • Launch a role. Read the role prompt linked in the Agent Architecture table. When the environment has a registered worker for the role, use its zeroize-audit:<role-name> identifier (for example, zeroize-audit:0-preflight); otherwise create an independent worker with the Markdown body of that prompt, the current phase's instructions, and its parameter values. Always include the resolved baseDir and, once created, workdir, even when a phase table does not repeat them. Resolve resource references using the rules above before delegation. Worker file/search/shell actions use the environment's actual tool schemas and permissions. The role's name identifies its instructions, not a required dispatch API or model.

  • Wait for results. Retain each worker's handle and wait through the environment's completion mechanism. A launch acknowledgement is not completion. Read the phase's required artifacts before updating its completion state or starting a dependent phase. On worker failure or unavailable dispatch, apply only that phase's documented fallback; otherwise record the failure in the existing run state and report the affected phase as blocked.

  • Concurrency. Respect available concurrency and phase barriers. Run workers sequentially when parallel execution is unavailable. Per-TU compiler workers write to separate directories and may run concurrently.

  • Collect decisions. Use the environment's user-input facility or ask in the conversation. When a phase requires an answer, wait for it; do not substitute a default or elapsed time for the user's decision. Preserve the validation and verification outcomes when recording any accepted or rejected PoC result.

How to Run

On a request like "audit this crate for secrets left in memory" or "check that this C library actually wipes its keys":

  1. Collect inputs. Map the request onto the Inputs table below (full schema: schemas/input.json). path is required, plus at least one of compile_db (C/C++) or cargo_manifest (Rust); if neither is given or derivable from the repo, ask the user, because preflight stops the run without one. Leave all other fields at their defaults unless the user says otherwise.

  2. Read the orchestrator prompt, substituting the collected inputs for its {{placeholder}} values. You act as the orchestrator it describes: it defines state recovery, the phase loop, early termination, and error handling. Read the shared instructions alongside it for the shared working-directory layout and the agent error protocol every phase depends on.

  3. Execute its phase loop. Run Phases 0-7 sequentially. Before each phase, read that phase's workflow file from {baseDir}/workflows/phase-{N}-{name}.md and follow its Preconditions, Instructions, State Update, and Error Handling sections. Each workflow specifies the role prompt and parameters to use under the Execution Contract above. Honor the per-phase skip conditions and the early-termination rules in task.md.

  4. Return the report (Phase 8, inline): read {workdir}/report/final-report.md and return its contents as the skill output.

To resume an interrupted run: if a workdir is known from prior context, read {workdir}/orchestrator-state.json and continue from its current_phase instead of starting at Phase 0 (see the Recovery section of task.md).


Purpose

Detect missing zeroization of sensitive data in source code and identify zeroization that is removed or weakened by compiler optimizations (e.g., dead-store elimination), with mandatory LLVM IR/asm evidence. Capabilities include:

  • Assembly-level analysis for register spills and stack retention

  • Data-flow tracking for secret copies

  • Heap allocator security warnings

  • Semantic IR analysis for loop unrolling and SSA form

  • Control-flow graph analysis for path coverage verification

  • Runtime validation test generation

Scope

  • Read-only against the target codebase (does not modify audited code; writes analysis artifacts to a temporary working directory).

  • Produces a structured report (JSON).

  • Requires valid build context (compile_commands.json) and compilable translation units.

  • "Optimized away" findings only allowed with compiler evidence (IR/asm diff).


Inputs

See schemas/input.json for the full schema. Key fields:

FieldRequiredDefaultDescription
pathyes—Repo root
compile_dbnonullPath to compile_commands.json for C/C++ analysis. Required if cargo_manifest is not set.
cargo_manifestnonullPath to Cargo.toml for Rust crate analysis. Required if compile_db is not set.
configno—YAML defining heuristics and approved wipes
opt_levelsno["O0","O1","O2"]Optimization levels for IR comparison. O1 is the diagnostic level: if a wipe disappears at O1 it is simple DSE; O2 catches more aggressive eliminations.
languagesno["c","cpp","rust"]Languages to analyze
max_tusno50Limit on translation units processed from compile DB
mcp_modenopreferoff, prefer, or require — controls Serena MCP usage
mcp_required_for_advancednotrueDowngrade SECRET_COPY, MISSING_ON_ERROR_PATH, and NOT_DOMINATING_EXITS to needs_review when MCP is unavailable
mcp_timeout_msno10000Timeout budget for MCP semantic queries
poc_categoriesnoall 11 exploitableFinding categories for which to generate PoCs. C/C++ findings: all 11 categories supported. Rust findings: only MISSING_SOURCE_ZEROIZE, SECRET_COPY, and PARTIAL_WIPE are supported; other Rust categories are marked poc_supported=false.
poc_output_dirnogenerated_pocs/Output directory for generated PoCs
enable_asmnotrueEnable assembly emission and analysis (Step 8); produces STACK_RETENTION, REGISTER_SPILL. Auto-disabled if emit_asm.sh is missing.
enable_semantic_irnofalseEnable semantic LLVM IR analysis (Step 9); produces LOOP_UNROLLED_INCOMPLETE
enable_cfgnofalseEnable control-flow graph analysis (Step 10); produces MISSING_ON_ERROR_PATH, NOT_DOMINATING_EXITS
enable_runtime_testsnofalseEnable runtime test harness generation (Step 11)

Prerequisites

Before running, verify the following. Each has a defined failure mode.

C/C++ prerequisites:

PrerequisiteFailure mode if missing
compile_commands.json at compile_db pathFail fast — do not proceed
clang on PATHFail fast — IR/ASM analysis impossible
uvx on PATH (for Serena)If mcp_mode=require: fail. If mcp_mode=prefer: continue without MCP; downgrade affected findings per Confidence Gating rules.
{baseDir}/tools/extract_compile_flags.pyFail fast — cannot extract per-TU flags
{baseDir}/tools/emit_ir.shFail fast — IR analysis impossible
{baseDir}/tools/emit_asm.shWarn and skip assembly findings (STACK_RETENTION, REGISTER_SPILL)
{baseDir}/tools/mcp/check_mcp.shWarn and treat as MCP unavailable
{baseDir}/tools/mcp/normalize_mcp_evidence.pyWarn and use raw MCP output

Rust prerequisites:

PrerequisiteFailure mode if missing
Cargo.toml at cargo_manifest pathFail fast — do not proceed
cargo check passesFail fast — crate must be buildable
cargo +nightly on PATHFail fast — nightly required for MIR and LLVM IR emission
uv on PATHFail fast — required to run Python analysis scripts
{baseDir}/tools/validate_rust_toolchain.shWarn — run preflight manually. Checks all tools, scripts, nightly, and optionally cargo check. Use --json for machine-readable output, --manifest to also validate the crate builds.
{baseDir}/tools/emit_rust_mir.shFail fast — MIR analysis impossible (--opt, --crate, --bin/--lib supported; --out can be file or directory)
{baseDir}/tools/emit_rust_ir.shFail fast — LLVM IR analysis impossible (--opt required; --crate, --bin/--lib supported; --out must be .ll)
{baseDir}/tools/emit_rust_asm.shWarn and skip assembly findings (STACK_RETENTION, REGISTER_SPILL). Supports --opt, --crate, --bin/--lib, --target, --intel-syntax; --out can be .s file or directory.
{baseDir}/tools/diff_rust_mir.shWarn and skip MIR-level optimization comparison. Accepts 2+ MIR files, normalizes, diffs pairwise, and reports first opt level where zeroize/drop-glue patterns disappear.
{baseDir}/tools/scripts/semantic_audit.pyWarn and skip semantic source analysis
{baseDir}/tools/scripts/find_dangerous_apis.pyWarn and skip dangerous API scan
{baseDir}/tools/scripts/check_mir_patterns.pyWarn and skip MIR analysis
{baseDir}/tools/scripts/check_llvm_patterns.pyWarn and skip LLVM IR analysis
{baseDir}/tools/scripts/check_rust_asm.pyWarn and skip Rust assembly analysis (STACK_RETENTION, REGISTER_SPILL, drop-glue checks). Dispatches to check_rust_asm_x86.py (production) or check_rust_asm_aarch64.py (EXPERIMENTAL — AArch64 findings require manual verification).
{baseDir}/tools/scripts/check_rust_asm_x86.pyRequired by check_rust_asm.py for x86-64 analysis; warn and skip if missing
{baseDir}/tools/scripts/check_rust_asm_aarch64.pyRequired by check_rust_asm.py for AArch64 analysis (EXPERIMENTAL); warn and skip if missing

Common prerequisite:

PrerequisiteFailure mode if missing
{baseDir}/tools/generate_poc.pyFail fast — PoC generation is mandatory

Approved Wipe APIs

The following are recognized as valid zeroization. Configure additional entries in {baseDir}/configs/.

C/C++

  • explicit_bzero

  • memset_s

  • SecureZeroMemory

  • OPENSSL_cleanse

  • sodium_memzero

  • Volatile wipe loops (pattern-based; see volatile_wipe_patterns in {baseDir}/configs/default.yaml)

  • In IR: llvm.memset with volatile flag, volatile stores, or non-elidable wipe call

Rust

  • zeroize::Zeroize trait (zeroize() method)

  • Zeroizing<T> wrapper (drop-based)

  • ZeroizeOnDrop derive macro


Finding Capabilities

Findings are grouped by required evidence. Only attempt findings for which the required tooling is available.

Finding IDDescriptionRequiresPoC Support
MISSING_SOURCE_ZEROIZENo zeroization found in sourceSource onlyYes (C/C++ + Rust)
PARTIAL_WIPEIncorrect size or incomplete wipeSource onlyYes (C/C++ + Rust)
NOT_ON_ALL_PATHSZeroization missing on some control-flow paths (heuristic)Source onlyYes (C/C++ only)
SECRET_COPYSensitive data copied without zeroization trackingSource + MCP preferredYes (C/C++ + Rust)
INSECURE_HEAP_ALLOCSecret uses insecure allocator (malloc vs. secure_malloc)Source onlyYes (C/C++ only)
OPTIMIZED_AWAY_ZEROIZECompiler removed zeroizationIR diff required (never source-only)Yes
STACK_RETENTIONStack frame may retain secrets after returnAssembly required (C/C++); LLVM IR alloca+lifetime.end evidence (Rust); assembly corroboration upgrades to confirmedYes (C/C++ only)
REGISTER_SPILLSecrets spilled from registers to stackAssembly required (C/C++); LLVM IR load+call-site evidence (Rust); assembly corroboration upgrades to confirmedYes (C/C++ only)
MISSING_ON_ERROR_PATHError-handling paths lack cleanupCFG or MCP requiredYes
NOT_DOMINATING_EXITSWipe doesn't dominate all exitsCFG or MCP requiredYes
LOOP_UNROLLED_INCOMPLETEUnrolled loop wipe is incompleteSemantic IR requiredYes

Agent Architecture

The analysis pipeline uses 11 worker roles across 8 phases, launched by the orchestrator using the Execution Contract above. Agents write persistent finding files to a shared working directory (/tmp/zeroize-audit-{run_id}/), enabling parallel execution and protecting against context pressure.

AgentPhasePurposeOutput Directory
0-preflightPhase 0Preflight checks (tools, toolchain, compile DB, crate build), config merge, workdir creation, TU enumeration{workdir}/
1-mcp-resolverPhase 1, Wave 1 (C/C++ only)Resolve symbols, types, and cross-file references via Serena MCPmcp-evidence/
2-source-analyzerPhase 1, Wave 2a (C/C++ only)Identify sensitive objects, detect wipes, validate correctness, data-flow/heapsource-analysis/
2b-rust-source-analyzerPhase 1, Wave 2b (Rust only, parallel with 2a)Rustdoc JSON trait-aware analysis + dangerous API grepsource-analysis/
3-tu-compiler-analyzerPhase 2, Wave 3 (C/C++ only, N parallel)Per-TU IR diff, assembly, semantic IR, CFG analysiscompiler-analysis/{tu_hash}/
3b-rust-compiler-analyzerPhase 2, Wave 3R (Rust only, single agent)Crate-level MIR, LLVM IR, and assembly analysisrust-compiler-analysis/
4-report-assemblerPhase 3 (interim) + Phase 6 (final)Collect findings from all agents, apply confidence gates; merge PoC results and produce final reportreport/
5-poc-generatorPhase 4Craft bespoke proof-of-concept programs (C/C++: all categories; Rust: MISSING_SOURCE_ZEROIZE, SECRET_COPY, PARTIAL_WIPE)poc/
5b-poc-validatorPhase 5Compile and run all PoCspoc/
5c-poc-verifierPhase 5Verify each PoC proves its claimed findingpoc/
6-test-generatorPhase 7 (optional)Generate runtime validation test harnessestests/

The orchestrator reads one per-phase workflow file from {baseDir}/workflows/ at a time, and maintains orchestrator-state.json for recovery after context compression. Agents receive configuration by file path (config_path), not by value.

Execution flow
Phase 0: 0-preflight agent — Preflight + config + create workdir + enumerate TUs
           → writes orchestrator-state.json, merged-config.yaml, preflight.json
Phase 1: Wave 1:  1-mcp-resolver              (skip if mcp_mode=off OR language_mode=rust)
         Wave 2a: 2-source-analyzer           (C/C++ only; skip if no compile_db)  ─┐ parallel
         Wave 2b: 2b-rust-source-analyzer     (Rust only; skip if no cargo_manifest) ─┘
Phase 2: Wave 3:  3-tu-compiler-analyzer x N  (C/C++ only; parallel per TU)
         Wave 3R: 3b-rust-compiler-analyzer   (Rust only; single crate-level agent)
Phase 3: Wave 4:  4-report-assembler          (mode=interim → findings.json; reads all agent outputs)
Phase 4: Wave 5:  5-poc-generator             (C/C++: all categories; Rust: MISSING_SOURCE_ZEROIZE, SECRET_COPY, PARTIAL_WIPE; other Rust findings: poc_supported=false)
Phase 5: PoC Validation & Verification
           Step 1: 5b-poc-validator agent      (compile and run all PoCs)
           Step 2: 5c-poc-verifier agent       (verify each PoC proves its claimed finding)
           Step 3: Orchestrator asks the user to accept or reject failed verification
           Step 4: Orchestrator merges all results into poc_final_results.json
Phase 6: Wave 6: 4-report-assembler           (mode=final → merge PoC results, final-report.md)
Phase 7: Wave 7: 6-test-generator             (optional)
Phase 8: Orchestrator — Return final-report.md

Cross-Reference Convention

IDs are namespaced per agent to prevent collisions during parallel execution:

EntityPatternAssigned By
Sensitive object (C/C++)SO-0001–SO-49992-source-analyzer
Sensitive object (Rust)SO-5000–SO-9999 (Rust namespace)2b-rust-source-analyzer
Source finding (C/C++)F-SRC-NNNN2-source-analyzer
Source finding (Rust)F-RUST-SRC-NNNN2b-rust-source-analyzer
IR finding (C/C++)F-IR-{tu_hash}-NNNN3-tu-compiler-analyzer
ASM finding (C/C++)F-ASM-{tu_hash}-NNNN3-tu-compiler-analyzer
CFG findingF-CFG-{tu_hash}-NNNN3-tu-compiler-analyzer
Semantic IR findingF-SIR-{tu_hash}-NNNN3-tu-compiler-analyzer
Rust MIR findingF-RUST-MIR-NNNN3b-rust-compiler-analyzer
Rust LLVM IR findingF-RUST-IR-NNNN3b-rust-compiler-analyzer
Rust assembly findingF-RUST-ASM-NNNN3b-rust-compiler-analyzer
Translation unitTU-{hash}Orchestrator
Final findingZA-NNNN4-report-assembler

Every finding JSON object includes related_objects, related_findings, and evidence_files fields for cross-referencing between agents.


Detection Strategy

Analysis runs in two phases. For complete step-by-step guidance, see {baseDir}/references/detection-strategy.md.

PhaseStepsFindings producedRequired tooling
Phase 1 (Source)1–6MISSING_SOURCE_ZEROIZE, PARTIAL_WIPE, NOT_ON_ALL_PATHS, SECRET_COPY, INSECURE_HEAP_ALLOCSource + compile DB
Phase 2 (Compiler)7–12OPTIMIZED_AWAY_ZEROIZE, STACK_RETENTION, REGISTER_SPILL, LOOP_UNROLLED_INCOMPLETE†, MISSING_ON_ERROR_PATH‡, NOT_DOMINATING_EXITS‡clang, IR/ASM tools

* requires enable_asm=true (default) † requires enable_semantic_ir=true ‡ requires enable_cfg=true

For Rust, {baseDir}/references/rust-zeroization-patterns.md catalogues 40 named anti-patterns, keyed to the script that detects each one: Section A for rustdoc-JSON semantics (semantic_audit.py), Section B for dangerous APIs (find_dangerous_apis.py), and Section C for MIR/LLVM IR/assembly (check_mir_patterns.py, check_llvm_patterns.py, check_rust_asm.py). Read the relevant section when triaging a Rust finding, writing its fix recommendation, or deciding whether a hand-spotted pattern is already covered.

Two limits on how far that reference goes. The 34 entries in Sections A-C are what the scripts detect today; Section D's six are known gaps no script covers, so treat those as unaudited rather than clean. Sections A and C are also partial — the scripts emit some classes with no entry — so a finding that matches no catalogued pattern is still a finding, carrying whatever evidence the script produced.


Output Format

Each run produces two outputs:

  1. final-report.md — Comprehensive markdown report (primary human-readable output)

  2. findings.json — Structured JSON matching {baseDir}/schemas/output.json (for machine consumption and downstream tools)

Markdown Report Structure

The markdown report (final-report.md) contains these sections:

  • Header: Run metadata (run_id, timestamp, repo, compile_db, config summary)

  • Executive Summary: Finding counts by severity, confidence, and category

  • Sensitive Objects Inventory: Table of all identified objects with IDs, types, locations

  • Findings: Grouped by severity then confidence. Each finding includes location, object, all evidence (source/IR/ASM/CFG), compiler evidence details, and recommended fix

  • Superseded Findings: Source findings replaced by CFG-backed findings

  • Confidence Gate Summary: Downgrades applied and overrides rejected

  • Analysis Coverage: TUs analyzed, agent success/failure, features enabled, and any Section D patterns the crate uses that no script audits

  • Appendix: Evidence Files: Mapping of finding IDs to evidence file paths

Structured JSON

The findings.json file follows the schema in {baseDir}/schemas/output.json. Each Finding object:

{
  "id": "ZA-0001",
  "category": "OPTIMIZED_AWAY_ZEROIZE",
  "severity": "high",
  "confidence": "confirmed",
  "language": "c",
  "file": "src/crypto.c",
  "line": 42,
  "symbol": "key_buf",
  "evidence": "store volatile i8 0 count: O0=32, O2=0 — wipe eliminated by DSE",
  "compiler_evidence": {
    "opt_levels": ["O0", "O2"],
    "o0": "32 volatile stores targeting key_buf",
    "o2": "0 volatile stores (all eliminated)",
    "diff_summary": "All volatile wipe stores removed at O2 — classic DSE pattern"
  },
  "suggested_fix": "Replace memset with explicit_bzero or add compiler_fence(SeqCst) after the wipe",
  "poc": {
    "file": "generated_pocs/ZA-0001.c",
    "makefile_target": "ZA-0001",
    "compile_opt": "-O2",
    "requires_manual_adjustment": false,
    "validated": true,
    "validation_result": "exploitable"
  }
}

See {baseDir}/schemas/output.json for the full schema and enum values.


Confidence Gating

Evidence thresholds

A finding requires at least 2 independent signals to be marked confirmed. With 1 signal, mark likely. With 0 strong signals (name-pattern match only), mark needs_review.

Signals include: name pattern match, type hint match, explicit annotation, IR evidence, ASM evidence, MCP cross-reference, CFG evidence, PoC validation.

PoC validation as evidence signal

Every finding is validated against a bespoke PoC. After compilation and execution, each PoC is also verified to ensure it actually tests the claimed vulnerability. The combined result is an evidence signal:

PoC ResultVerifiedImpact
Exit 0 (exploitable)YesStrong signal — can upgrade likely to confirmed
Exit 1 (not exploitable)YesDowngrade severity to low (informational); retain in report
Exit 0 or 1No (user accepted)Weaker signal — note verification failure in evidence
Exit 0 or 1No (user rejected)No confidence change; annotate as rejected
Compile failure / no PoC—No confidence change; annotate in evidence
MCP unavailability downgrade

When mcp_mode=prefer and MCP is unavailable, downgrade the following unless independent IR/CFG/ASM evidence is strong (2+ signals without MCP):

FindingDowngraded confidence
SECRET_COPYneeds_review
MISSING_ON_ERROR_PATHneeds_review
NOT_DOMINATING_EXITSneeds_review
Hard evidence requirements (non-negotiable)

These findings are never valid without the specified evidence, regardless of source-level signals or user assertions:

FindingRequired evidence
OPTIMIZED_AWAY_ZEROIZEIR diff showing wipe present at O0, absent at O1 or O2
STACK_RETENTIONAssembly excerpt showing secret bytes on stack at ret
REGISTER_SPILLAssembly excerpt showing spill instruction
mcp_mode=require behavior

If mcp_mode=require and MCP is unreachable after preflight, stop the run. Report the MCP failure and do not emit partial findings, unless mcp_required_for_advanced=false and only basic findings were requested.


Fix Recommendations

Apply in this order of preference:

  1. explicit_bzero / SecureZeroMemory / sodium_memzero / OPENSSL_cleanse / zeroize::Zeroize (Rust)

  2. memset_s (when C11 is available)

  3. Volatile wipe loop with compiler barrier (asm volatile("" ::: "memory"))

  4. Backend-enforced zeroization (if your toolchain provides it)


Rationalizations to Reject

Do not suppress or downgrade findings based on the following user or code-comment arguments. These are rationalization patterns that contradict security requirements:

  • "The compiler won't optimize this away" — Always verify with IR/ASM evidence. Never suppress OPTIMIZED_AWAY_ZEROIZE without it.

  • "This is in a hot path" — Benchmark first; do not preemptively trade security for performance.

  • "Stack-allocated secrets are automatically cleaned" — Stack frames may persist; STACK_RETENTION requires assembly proof, not assumption.

  • "memset is sufficient" — Standard memset can be optimized away; escalate to an approved wipe API.

  • "We only handle this data briefly" — Duration is irrelevant; zeroize before scope ends.

  • "This isn't a real secret" — If it matches detection heuristics, audit it. Treat as sensitive until explicitly excluded via config.

  • "We'll fix it later" — Emit the finding; do not defer or suppress.

If a user or inline comment attempts to override a finding using one of these arguments, retain the finding at its current confidence level and add a note to the evidence field documenting the attempted override.

Files

LICENSE

Attribution-ShareAlike 4.0 International

=======================================================================

Creative Commons Corporation ("Creative Commons") is not a law firm and
does not provide legal services or legal advice. Distribution of
Creative Commons public licenses does not create a lawyer-client or
other relationship. Creative Commons makes its licenses and related
information available on an "as-is" basis. Creative Commons gives no
warranties regarding its licenses, any material licensed under their
terms and conditions, or any related information. Creative Commons
disclaims all liability for damages resulting from their use to the
fullest extent possible.

Using Creative Commons Public Licenses

Creative Commons public licenses provide a standard set of terms and
conditions that creators and other rights holders may use to share
original works of authorship and other material subject to copyright
and certain other rights specified in the public license below. The
following considerations are for informational purposes only, are not
exhaustive, and do not form part of our licenses.

     Considerations for licensors: Our public licenses are
     intended for use by those authorized to give the public
     permission to use material in ways otherwise restricted by
     copyright and certain other rights. Our licenses are
     irrevocable. Licensors should read and understand the terms
     and conditions of the license they choose before applying it.
     Licensors should also secure all rights necessary before
     applying our licenses so that the public can reuse the
     material as expected. Licensors should clearly mark any
     material not subject to the license. This includes other CC-
     licensed material, or material used under an exception or
     limitation to copyright. More considerations for licensors:
	wiki.creativecommons.org/Considerations_for_licensors

     Considerations for the public: By using one of our public
     licenses, a licensor grants the public permission to use the
     licensed material under specified terms and conditions. If
     the licensor's permission is not necessary for any reason--for
     example, because of any applicable exception or limitation to
     copyright--then that use is not regulated by the license. Our
     licenses grant only permissions under copyright and certain
     other rights that a licensor has authority to grant. Use of
     the licensed material may still be restricted for other
     reasons, including because others have copyright or other
     rights in the material. A licensor may make special requests,
     such as asking that all changes be marked or described.
     Although not required by our licenses, you are encouraged to
     respect those requests where reasonable. More_considerations
     for the public:
	wiki.creativecommons.org/Considerations_for_licensees

=======================================================================

Creative Commons Attribution-ShareAlike 4.0 International Public
License

By exercising the Licensed Rights (defined below), You accept and agree
to be bound by the terms and conditions of this Creative Commons
Attribution-ShareAlike 4.0 International Public License ("Public
License"). To the extent this Public License may be interpreted as a
contract, You are granted the Licensed Rights in consideration of Your
acceptance of these terms and conditions, and the Licensor grants You
such rights in consideration of benefits the Licensor receives from
making the Licensed Material available under these terms and
conditions.


Section 1 -- Definitions.

  a. Adapted Material means material subject to Copyright and Similar
     Rights that is derived from or based upon the Licensed Material
     and in which the Licensed Material is translated, altered,
     arranged, transformed, or otherwise modified in a manner requiring
     permission under the Copyright and Similar Rights held by the
     Licensor. For purposes of this Public License, where the Licensed
     Material is a musical work, performance, or sound recording,
     Adapted Material is always produced where the Licensed Material is
     synched in timed relation with a moving image.

  b. Adapter's License means the license You apply to Your Copyright
     and Similar Rights in Your contributions to Adapted Material in
     accordance with the terms and conditions of this Public License.

  c. BY-SA Compatible License means a license listed at
     creativecommons.org/compatiblelicenses, approved by Creative
     Commons as essentially the equivalent of this Public License.

  d. Copyright and Similar Rights means copyright and/or similar rights
     closely related to copyright including, without limitation,
     performance, broadcast, sound recording, and Sui Generis Database
     Rights, without regard to how the rights are labeled or
     categorized. For purposes of this Public License, the rights
     specified in Section 2(b)(1)-(2) are not Copyright and Similar
     Rights.

  e. Effective Technological Measures means those measures that, in the
     absence of proper authority, may not be circumvented under laws
     fulfilling obligations under Article 11 of the WIPO Copyright
     Treaty adopted on December 20, 1996, and/or similar international
     agreements.

  f. Exceptions and Limitations means fair use, fair dealing, and/or
     any other exception or limitation to Copyright and Similar Rights
     that applies to Your use of the Licensed Material.

  g. License Elements means the license attributes listed in the name
     of a Creative Commons Public License. The License Elements of this
     Public License are Attribution and ShareAlike.

  h. Licensed Material means the artistic or literary work, database,
     or other material to which the Licensor applied this Public
     License.

  i. Licensed Rights means the rights granted to You subject to the
     terms and conditions of this Public License, which are limited to
     all Copyright and Similar Rights that apply to Your use of the
     Licensed Material and that the Licensor has authority to license.

  j. Licensor means the individual(s) or entity(ies) granting rights
     under this Public License.

  k. Share means to provide material to the public by any means or
     process that requires permission under the Licensed Rights, such
     as reproduction, public display, public performance, distribution,
     dissemination, communication, or importation, and to make material
     available to the public including in ways that members of the
     public may access the material from a place and at a time
     individually chosen by them.

  l. Sui Generis Database Rights means rights other than copyright
     resulting from Directive 96/9/EC of the European Parliament and of
     the Council of 11 March 1996 on the legal protection of databases,
     as amended and/or succeeded, as well as other essentially
     equivalent rights anywhere in the world.

  m. You means the individual or entity exercising the Licensed Rights
     under this Public License. Your has a corresponding meaning.


Section 2 -- Scope.

  a. License grant.

       1. Subject to the terms and conditions of this Public License,
          the Licensor hereby grants You a worldwide, royalty-free,
          non-sublicensable, non-exclusive, irrevocable license to
          exercise the Licensed Rights in the Licensed Material to:

            a. reproduce and Share the Licensed Material, in whole or
               in part; and

            b. produce, reproduce, and Share Adapted Material.

       2. Exceptions and Limitations. For the avoidance of doubt, where
          Exceptions and Limitations apply to Your use, this Public
          License does not apply, and You do not need to comply with
          its terms and conditions.

       3. Term. The term of this Public License is specified in Section
          6(a).

       4. Media and formats; technical modifications allowed. The
          Licensor authorizes You to exercise the Licensed Rights in
          all media and formats whether now known or hereafter created,
          and to make technical modifications necessary to do so. The
          Licensor waives and/or agrees not to assert any right or
          authority to forbid You from making technical modifications
          necessary to exercise the Licensed Rights, including
          technical modifications necessary to circumvent Effective
          Technological Measures. For purposes of this Public License,
          simply making modifications authorized by this Section 2(a)
          (4) never produces Adapted Material.

       5. Downstream recipients.

            a. Offer from the Licensor -- Licensed Material. Every
               recipient of the Licensed Material automatically
               receives an offer from the Licensor to exercise the
               Licensed Rights under the terms and conditions of this
               Public License.

            b. Additional offer from the Licensor -- Adapted Material.
               Every recipient of Adapted Material from You
               automatically receives an offer from the Licensor to
               exercise the Licensed Rights in the Adapted Material
               under the conditions of the Adapter's License You apply.

            c. No downstream restrictions. You may not offer or impose
               any additional or different terms or conditions on, or
               apply any Effective Technological Measures to, the
               Licensed Material if doing so restricts exercise of the
               Licensed Rights by any recipient of the Licensed
               Material.

       6. No endorsement. Nothing in this Public License constitutes or
          may be construed as permission to assert or imply that You
          are, or that Your use of the Licensed Material is, connected
          with, or sponsored, endorsed, or granted official status by,
          the Licensor or others designated to receive attribution as
          provided in Section 3(a)(1)(A)(i).

  b. Other rights.

       1. Moral rights, such as the right of integrity, are not
          licensed under this Public License, nor are publicity,
          privacy, and/or other similar personality rights; however, to
          the extent possible, the Licensor waives and/or agrees not to
          assert any such rights held by the Licensor to the limited
          extent necessary to allow You to exercise the Licensed
          Rights, but not otherwise.

       2. Patent and trademark rights are not licensed under this
          Public License.

       3. To the extent possible, the Licensor waives any right to
          collect royalties from You for the exercise of the Licensed
          Rights, whether directly or through a collecting society
          under any voluntary or waivable statutory or compulsory
          licensing scheme. In all other cases the Licensor expressly
          reserves any right to collect such royalties.


Section 3 -- License Conditions.

Your exercise of the Licensed Rights is expressly made subject to the
following conditions.

  a. Attribution.

       1. If You Share the Licensed Material (including in modified
          form), You must:

            a. retain the following if it is supplied by the Licensor
               with the Licensed Material:

                 i. identification of the creator(s) of the Licensed
                    Material and any others designated to receive
                    attribution, in any reasonable manner requested by
                    the Licensor (including by pseudonym if
                    designated);

                ii. a copyright notice;

               iii. a notice that refers to this Public License;

                iv. a notice that refers to the disclaimer of
                    warranties;

                 v. a URI or hyperlink to the Licensed Material to the
                    extent reasonably practicable;

            b. indicate if You modified the Licensed Material and
               retain an indication of any previous modifications; and

            c. indicate the Licensed Material is licensed under this
               Public License, and include the text of, or the URI or
               hyperlink to, this Public License.

       2. You may satisfy the conditions in Section 3(a)(1) in any
          reasonable manner based on the medium, means, and context in
          which You Share the Licensed Material. For example, it may be
          reasonable to satisfy the conditions by providing a URI or
          hyperlink to a resource that includes the required
          information.

       3. If requested by the Licensor, You must remove any of the
          information required by Section 3(a)(1)(A) to the extent
          reasonably practicable.

  b. ShareAlike.

     In addition to the conditions in Section 3(a), if You Share
     Adapted Material You produce, the following conditions also apply.

       1. The Adapter's License You apply must be a Creative Commons
          license with the same License Elements, this version or
          later, or a BY-SA Compatible License.

       2. You must include the text of, or the URI or hyperlink to, the
          Adapter's License You apply. You may satisfy this condition
          in any reasonable manner based on the medium, means, and
          context in which You Share Adapted Material.

       3. You may not offer or impose any additional or different terms
          or conditions on, or apply any Effective Technological
          Measures to, Adapted Material that restrict exercise of the
          rights granted under the Adapter's License You apply.


Section 4 -- Sui Generis Database Rights.

Where the Licensed Rights include Sui Generis Database Rights that
apply to Your use of the Licensed Material:

  a. for the avoidance of doubt, Section 2(a)(1) grants You the right
     to extract, reuse, reproduce, and Share all or a substantial
     portion of the contents of the database;

  b. if You include all or a substantial portion of the database
     contents in a database in which You have Sui Generis Database
     Rights, then the database in which You have Sui Generis Database
     Rights (but not its individual contents) is Adapted Material,

     including for purposes of Section 3(b); and
  c. You must comply with the conditions in Section 3(a) if You Share
     all or a substantial portion of the contents of the database.

For the avoidance of doubt, this Section 4 supplements and does not
replace Your obligations under this Public License where the Licensed
Rights include other Copyright and Similar Rights.


Section 5 -- Disclaimer of Warranties and Limitation of Liability.

  a. UNLESS OTHERWISE SEPARATELY UNDERTAKEN BY THE LICENSOR, TO THE
     EXTENT POSSIBLE, THE LICENSOR OFFERS THE LICENSED MATERIAL AS-IS
     AND AS-AVAILABLE, AND MAKES NO REPRESENTATIONS OR WARRANTIES OF
     ANY KIND CONCERNING THE LICENSED MATERIAL, WHETHER EXPRESS,
     IMPLIED, STATUTORY, OR OTHER. THIS INCLUDES, WITHOUT LIMITATION,
     WARRANTIES OF TITLE, MERCHANTABILITY, FITNESS FOR A PARTICULAR
     PURPOSE, NON-INFRINGEMENT, ABSENCE OF LATENT OR OTHER DEFECTS,
     ACCURACY, OR THE PRESENCE OR ABSENCE OF ERRORS, WHETHER OR NOT
     KNOWN OR DISCOVERABLE. WHERE DISCLAIMERS OF WARRANTIES ARE NOT
     ALLOWED IN FULL OR IN PART, THIS DISCLAIMER MAY NOT APPLY TO YOU.

  b. TO THE EXTENT POSSIBLE, IN NO EVENT WILL THE LICENSOR BE LIABLE
     TO YOU ON ANY LEGAL THEORY (INCLUDING, WITHOUT LIMITATION,
     NEGLIGENCE) OR OTHERWISE FOR ANY DIRECT, SPECIAL, INDIRECT,
     INCIDENTAL, CONSEQUENTIAL, PUNITIVE, EXEMPLARY, OR OTHER LOSSES,
     COSTS, EXPENSES, OR DAMAGES ARISING OUT OF THIS PUBLIC LICENSE OR
     USE OF THE LICENSED MATERIAL, EVEN IF THE LICENSOR HAS BEEN
     ADVISED OF THE POSSIBILITY OF SUCH LOSSES, COSTS, EXPENSES, OR
     DAMAGES. WHERE A LIMITATION OF LIABILITY IS NOT ALLOWED IN FULL OR
     IN PART, THIS LIMITATION MAY NOT APPLY TO YOU.

  c. The disclaimer of warranties and limitation of liability provided
     above shall be interpreted in a manner that, to the extent
     possible, most closely approximates an absolute disclaimer and
     waiver of all liability.


Section 6 -- Term and Termination.

  a. This Public License applies for the term of the Copyright and
     Similar Rights licensed here. However, if You fail to comply with
     this Public License, then Your rights under this Public License
     terminate automatically.

  b. Where Your right to use the Licensed Material has terminated under
     Section 6(a), it reinstates:

       1. automatically as of the date the violation is cured, provided
          it is cured within 30 days of Your discovery of the
          violation; or

       2. upon express reinstatement by the Licensor.

     For the avoidance of doubt, this Section 6(b) does not affect any
     right the Licensor may have to seek remedies for Your violations
     of this Public License.

  c. For the avoidance of doubt, the Licensor may also offer the
     Licensed Material under separate terms or conditions or stop
     distributing the Licensed Material at any time; however, doing so
     will not terminate this Public License.

  d. Sections 1, 5, 6, 7, and 8 survive termination of this Public
     License.


Section 7 -- Other Terms and Conditions.

  a. The Licensor shall not be bound by any additional or different
     terms or conditions communicated by You unless expressly agreed.

  b. Any arrangements, understandings, or agreements regarding the
     Licensed Material not stated herein are separate from and
     independent of the terms and conditions of this Public License.


Section 8 -- Interpretation.

  a. For the avoidance of doubt, this Public License does not, and
     shall not be interpreted to, reduce, limit, restrict, or impose
     conditions on any use of the Licensed Material that could lawfully
     be made without permission under this Public License.

  b. To the extent possible, if any provision of this Public License is
     deemed unenforceable, it shall be automatically reformed to the
     minimum extent necessary to make it enforceable. If the provision
     cannot be reformed, it shall be severed from this Public License
     without affecting the enforceability of the remaining terms and
     conditions.

  c. No term or condition of this Public License will be waived and no
     failure to comply consented to unless expressly agreed to by the
     Licensor.

  d. Nothing in this Public License constitutes or may be interpreted
     as a limitation upon, or waiver of, any privileges and immunities
     that apply to the Licensor or You, including from the legal
     processes of any jurisdiction or authority.


=======================================================================

Creative Commons is not a party to its public
licenses. Notwithstanding, Creative Commons may elect to apply one of
its public licenses to material it publishes and in those instances
will be considered the “Licensor.” The text of the Creative Commons
public licenses is dedicated to the public domain under the CC0 Public
Domain Dedication. Except for the limited purpose of indicating that
material is shared under a Creative Commons public license or as
otherwise permitted by the Creative Commons policies published at
creativecommons.org/policies, Creative Commons does not authorize the
use of the trademark "Creative Commons" or any other trademark or logo
of Creative Commons without its prior written consent including,
without limitation, in connection with any unauthorized modifications
to any of its public licenses or any other arrangements,
understandings, or agreements concerning use of licensed material. For
the avoidance of doubt, this paragraph does not form part of the
public licenses.

Creative Commons may be contacted at creativecommons.org.

Requirements and compatibility

Works with: Claude Code, Claude apps, OpenAI Codex, GitHub Copilot, Cursor, Gemini CLI, Kiro, OpenCode, Goose, Amp, Roo Code, JetBrains Junie, Factory Droid, Devin (ex-Windsurf), Mistral Vibe, OpenHands, Letta

“Works with” means the tool reads the open Agent Skills format; a skill written for one tool may use features others lack.

Needs: Declares allowed tools, Needs Python

Security

What our scanner noticed· Low risk

  • Scripts that your agent may run

This skill includes scripts that your agent may run. Read them before you use it.

A static scan is not a guarantee. Skills are third-party content: review a skill before you let an agent use it.

Attribution and licence

Published by
Trail of Bits
Publisher
Trail of Bits (Official)
Source
trailofbits/skills · plugins/zeroize-audit/skills/zeroize-audit · commit e4dd0bb
Licence
Creative Commons Attribution-ShareAlike 4.0 International (redistribution allowed)
  • LICENSE (added by AutoGineer from LICENSE)
  • ATTRIBUTION.md (written by AutoGineer)
Synced

AutoGineer is not affiliated with or endorsed by Trail of Bits or Trail of Bits.

Download ZIP

The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download zeroize-audit.zip