Gha Security Review

SentryOfficialPublished by Sentry

Skill
Review and audit
Cloud and DevOps
Apache-2.0
Medium risk

From the author

GitHub Actions security review for workflow exploitation vulnerabilities. Use when asked to "review GitHub Actions", "audit workflows", "check CI security", "GHA security", "workflow security review", or review .github/workflows/ for pwn requests, expression injection, credential theft, and supply chain attacks. Exploitation-focused with concrete PoC scenarios.

— the description by Sentry

AutoGineer summary

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

This skill provides a structured methodology for auditing GitHub Actions workflows to identify exploitable vulnerabilities. It focuses on real-world attack patterns such as pwn requests, expression injection, credential theft, and supply chain attacks. The skill requires users to trace complete attack paths and provide concrete proof-of-concept scenarios for any reported findings, ensuring that only actionable, high-confidence vulnerabilities are identified.

What it does

Audits .github/workflows/ and associated configuration files for security flaws.
Identifies vulnerabilities exploitable by external attackers without repository write access.
Maps workflow triggers to specific threat models like pull_request_target or issue_comment.
Provides guidance on validating findings through attack path tracing.
Categorizes findings by confidence level to prioritize actionable security issues.
Suggests remediation steps for confirmed vulnerabilities.

When to use it

When you need to perform a security audit of your GitHub Actions CI/CD pipeline.
When investigating potential workflow exploitation vectors in a repository.
When reviewing pull requests for CI/CD configuration security.
When you need to verify if a workflow is susceptible to external attacker manipulation.

Advantages

Focuses on concrete, exploitable attack paths rather than theoretical risks.
Reduces noise by excluding vulnerabilities that require repository write access.
Provides clear, actionable criteria for classifying findings.
Includes specific detection patterns for common CI/CD vulnerabilities.

Usage examples

“Review my GitHub Actions workflows for security vulnerabilities.”: The agent will scan the .github/workflows/ directory, analyze triggers and permissions, and report any high or medium confidence vulnerabilities with a PoC.
“Check if my CI is vulnerable to pwn requests.”: The agent will specifically audit workflows using pull_request_target and check if they unsafely check out or execute code from forks.
“Audit my issue_comment workflows for command injection.”: The agent will examine workflows triggered by issue_comment to ensure they include proper author_association checks to prevent unauthorized command execution.

Install

Download the skill as a ZIP:
https://autogineer.com/agent-skills/getsentry/gha-security-review/download

Unzip it into the cross-client skills folder of your project:

mkdir -p .agents/skills && unzip gha-security-review.zip -d .agents/skills

Documentation by Sentry

GitHub Actions Security Review

Find exploitable vulnerabilities in GitHub Actions workflows. Every finding MUST include a concrete exploitation scenario — if you can't build the attack, don't report it.

This skill encodes attack patterns from real GitHub Actions exploits — not generic CI/CD theory.

Scope

Review the workflows provided (file, diff, or repo). Research the codebase as needed to trace complete attack paths before reporting.

Files to Review

.github/workflows/*.yml — all workflow definitions
action.yml / action.yaml — composite actions in the repo
.github/actions/*/action.yml — local reusable actions
Config files loaded by workflows: CLAUDE.md, AGENTS.md, Makefile, shell scripts under .github/

Out of Scope

Workflows in other repositories (only note the dependency)
GitHub App installation permissions (note if relevant)

Threat Model

Only report vulnerabilities exploitable by an external attacker — someone without write access to the repository. The attacker can open PRs from forks, create issues, and post comments. They cannot push to branches, trigger workflow_dispatch, or trigger manual workflows.

Do not flag vulnerabilities that require write access to exploit:

workflow_dispatch input injection — requires write access to trigger
Expression injection in push-only workflows on protected branches
workflow_call input injection where all callers are internal
Secrets in workflow_dispatch/schedule-only workflows

Confidence

Report only HIGH and MEDIUM confidence findings. Do not report theoretical issues.

Confidence	Criteria	Action
HIGH	Traced the full attack path, confirmed exploitable	Report with exploitation scenario and fix
MEDIUM	Attack path partially confirmed, uncertain link	Report as needs verification
LOW	Theoretical or mitigated elsewhere	Do not report

For each HIGH finding, provide all five elements:

Entry point — How does the attacker get in? (fork PR, issue comment, branch name, etc.)
Payload — What does the attacker send? (actual code/YAML/input)
Execution mechanism — How does the payload run? (expression expansion, checkout + script, etc.)
Impact — What does the attacker gain? (token theft, code execution, repo write access)
PoC sketch — Concrete steps an attacker would follow

If you cannot construct all five, report as MEDIUM (needs verification).

Step 1: Classify Triggers and Load References

For each workflow, identify triggers and load the appropriate reference:

Trigger / Pattern	Load Reference
`pull_request_target`	`references/pwn-request.md`
`issue_comment` with command parsing	`references/comment-triggered-commands.md`
`${{ }}` in `run:` blocks	`references/expression-injection.md`
PATs / deploy keys / elevated credentials	`references/credential-escalation.md`
Checkout PR code + config file loading	`references/ai-prompt-injection-via-ci.md`
Third-party actions (especially unpinned)	`references/supply-chain.md`
`permissions:` block or secrets usage	`references/permissions-and-secrets.md`
Self-hosted runners, cache/artifact usage	`references/runner-infrastructure.md`
Any confirmed finding	`references/real-world-attacks.md`

Load references selectively — only what's relevant to the triggers found.

Step 2: Check for Vulnerability Classes

Check 1: Pwn Request

Does the workflow use pull_request_target AND check out fork code?

Look for actions/checkout with ref: pointing to PR head
Look for local actions (./.github/actions/) that would come from the fork
Check if any run: step executes code from the checked-out PR

Check 2: Expression Injection

Are ${{ }} expressions used inside run: blocks in externally-triggerable workflows?

Map every ${{ }} expression in every run: step
Confirm the value is attacker-controlled (PR title, branch name, comment body — not numeric IDs, SHAs, or repository names)
Confirm the expression is in a run: block, not if:, with:, or job-level env:

Check 3: Unauthorized Command Execution

Does an issue_comment-triggered workflow execute commands without authorization?

Is there an author_association check?
Can any GitHub user trigger the command?
Does the command handler also use injectable expressions?

Check 4: Credential Escalation

Are elevated credentials (PATs, deploy keys) accessible to untrusted code?

What's the blast radius of each secret?
Could a compromised workflow steal long-lived tokens?

Check 5: Config File Poisoning

Does the workflow load configuration from PR-supplied files?

AI agent instructions: CLAUDE.md, AGENTS.md, .cursorrules
Build configuration: Makefile, shell scripts

Check 6: Supply Chain

Are third-party actions securely pinned to full SHAs?

Pin third-party / external actions and reusable workflows only
Do not flag first-party actions/* or github/* on version tags
Do not flag same-repo / vendored (./.github/actions/...) as supply-chain pinning issues
Only report when the job has secrets, OIDC, write token, release, deploy, package, or signing power — unprivileged read-only CI is not a finding

Check 7: Permissions and Secrets

Are workflow permissions minimal? Are secrets properly scoped?

Check 8: Runner Infrastructure

Are self-hosted runners, caches, or artifacts used securely?

Safe Patterns (Do Not Flag)

Before reporting, check if the pattern is actually safe:

Pattern	Why Safe
`pull_request_target` WITHOUT checkout of fork code	Never executes attacker code
`${{ github.event.pull_request.number }}` in `run:`	Numeric only — not injectable
`${{ github.repository }}` / `github.repository_owner`	Repo owner controls this
`${{ secrets.* }}`	Not an expression injection vector
`${{ }}` in `if:` conditions	Evaluated by Actions runtime, not shell
`${{ }}` in `with:` inputs	Passed as string parameters, not shell-evaluated
Third-party actions pinned to full SHA	Immutable reference
First-party `actions/` / `github/` on version tags	Outside third-party pinning policy — do not flag
Same-repo / vendored local actions	Not third-party supply chain (review pwn-request separately)
`pull_request` trigger (not `_target`)	Runs in fork context with read-only token
Any expression in `workflow_dispatch`/`schedule`/`push` to protected branches	Requires write access — outside threat model

Key distinction: ${{ }} is dangerous in run: blocks (shell expansion) but safe in if:, with:, and env: at the job/step level (Actions runtime evaluation).

Step 3: Validate Before Reporting

Before including any finding, read the actual workflow YAML and trace the complete attack path:

Read the full workflow — don't rely on grep output alone
Trace the trigger — confirm the event and check if: conditions that gate execution
Trace the expression/checkout — confirm it's in a run: block or actually references fork code
Confirm attacker control — verify the value maps to something an external attacker sets
Check existing mitigations — env var wrapping, author_association checks, restricted permissions, SHA pinning

If any link is broken, mark MEDIUM (needs verification) or drop the finding.

If no checks produced a finding, report zero findings. Do not invent issues.

Step 4: Report Findings

## GitHub Actions Security Review

### Findings

#### [GHA-001] [Title] (Severity: Critical/High/Medium)
- **Workflow**: `.github/workflows/release.yml:15`
- **Trigger**: `pull_request_target`
- **Confidence**: HIGH — confirmed through attack path tracing
- **Exploitation Scenario**:
  1. [Step-by-step attack]
- **Impact**: [What attacker gains]
- **Fix**: [Code that fixes the issue]

### Needs Verification
[MEDIUM confidence items with explanation of what to verify]

### Reviewed and Cleared
[Workflows reviewed and confirmed safe]

If no findings: "No exploitable vulnerabilities identified. All workflows reviewed and cleared."

Files

ATTRIBUTION.mdAdded by AutoGineer862 B
LICENSELicence file added by AutoGineer10.5 KiB
SKILL.md8.8 KiB
references/ai-prompt-injection-via-ci.md5.3 KiB
references/comment-triggered-commands.md5.5 KiB
references/credential-escalation.md6.5 KiB
references/expression-injection.md8.4 KiB
references/permissions-and-secrets.md7.7 KiB
references/pwn-request.md5.8 KiB
references/real-world-attacks.md9.2 KiB
references/runner-infrastructure.md7.9 KiB
references/supply-chain.md9.4 KiB

LICENSE

                                 Apache License
                           Version 2.0, January 2004
                        http://www.apache.org/licenses/

   TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION

   1. Definitions.

      "License" shall mean the terms and conditions for use, reproduction,
      and distribution as defined by Sections 1 through 9 of this document.

      "Licensor" shall mean the copyright owner or entity authorized by
      the copyright owner that is granting the License.

      "Legal Entity" shall mean the union of the acting entity and all
      other entities that control, are controlled by, or are under common
      control with that entity. For the purposes of this definition,
      "control" means (i) the power, direct or indirect, to cause the
      direction or management of such entity, whether by contract or
      otherwise, or (ii) ownership of fifty percent (50%) or more of the
      outstanding shares, or (iii) beneficial ownership of such entity.

      "You" (or "Your") shall mean an individual or Legal Entity
      exercising permissions granted by this License.

      "Source" form shall mean the preferred form for making modifications,
      including but not limited to software source code, documentation
      source, and configuration files.

      "Object" form shall mean any form resulting from mechanical
      transformation or translation of a Source form, including but
      not limited to compiled object code, generated documentation,
      and conversions to other media types.

      "Work" shall mean the work of authorship, whether in Source or
      Object form, made available under the License, as indicated by a
      copyright notice that is included in or attached to the work
      (an example is provided in the Appendix below).

      "Derivative Works" shall mean any work, whether in Source or Object
      form, that is based on (or derived from) the Work and for which the
      editorial revisions, annotations, elaborations, or other modifications
      represent, as a whole, an original work of authorship. For the purposes
      of this License, Derivative Works shall not include works that remain
      separable from, or merely link (or bind by name) to the interfaces of,
      the Work and Derivative Works thereof.

      "Contribution" shall mean any work of authorship, including
      the original version of the Work and any modifications or additions
      to that Work or Derivative Works thereof, that is intentionally
      submitted to the Licensor for inclusion in the Work by the copyright owner
      or by an individual or Legal Entity authorized to submit on behalf of
      the copyright owner. For the purposes of this definition, "submitted"
      means any form of electronic, verbal, or written communication sent
      to the Licensor or its representatives, including but not limited to
      communication on electronic mailing lists, source code control systems,
      and issue tracking systems that are managed by, or on behalf of, the
      Licensor for the purpose of discussing and improving the Work, but
      excluding communication that is conspicuously marked or otherwise
      designated in writing by the copyright owner as "Not a Contribution."

      "Contributor" shall mean Licensor and any individual or Legal Entity
      on behalf of whom a Contribution has been received by Licensor and
      subsequently incorporated within the Work.

   2. Grant of Copyright License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      copyright license to reproduce, prepare Derivative Works of,
      publicly display, publicly perform, sublicense, and distribute the
      Work and such Derivative Works in Source or Object form.

   3. Grant of Patent License. Subject to the terms and conditions of
      this License, each Contributor hereby grants to You a perpetual,
      worldwide, non-exclusive, no-charge, royalty-free, irrevocable
      (except as stated in this section) patent license to make, have made,
      use, offer to sell, sell, import, and otherwise transfer the Work,
      where such license applies only to those patent claims licensable
      by such Contributor that are necessarily infringed by their
      Contribution(s) alone or by combination of their Contribution(s)
      with the Work to which such Contribution(s) was submitted. If You
      institute patent litigation against any entity (including a
      cross-claim or counterclaim in a lawsuit) alleging that the Work
      or a Contribution incorporated within the Work constitutes direct
      or contributory patent infringement, then any patent licenses
      granted to You under this License for that Work shall terminate
      as of the date such litigation is filed.

   4. Redistribution. You may reproduce and distribute copies of the
      Work or Derivative Works thereof in any medium, with or without
      modifications, and in Source or Object form, provided that You
      meet the following conditions:

      (a) You must give any other recipients of the Work or
          Derivative Works a copy of this License; and

      (b) You must cause any modified files to carry prominent notices
          stating that You changed the files; and

      (c) You must retain, in the Source form of any Derivative Works
          that You distribute, all copyright, patent, trademark, and
          attribution notices from the Source form of the Work,
          excluding those notices that do not pertain to any part of
          the Derivative Works; and

      (d) If the Work includes a "NOTICE" text file as part of its
          distribution, then any Derivative Works that You distribute must
          include a readable copy of the attribution notices contained
          within such NOTICE file, excluding those notices that do not
          pertain to any part of the Derivative Works, in at least one
          of the following places: within a NOTICE text file distributed
          as part of the Derivative Works; within the Source form or
          documentation, if provided along with the Derivative Works; or,
          within a display generated by the Derivative Works, if and
          wherever such third-party notices normally appear. The contents
          of the NOTICE file are for informational purposes only and
          do not modify the License. You may add Your own attribution
          notices within Derivative Works that You distribute, alongside
          or as an addendum to the NOTICE text from the Work, provided
          that such additional attribution notices cannot be construed
          as modifying the License.

      You may add Your own copyright statement to Your modifications and
      may provide additional or different license terms and conditions
      for use, reproduction, or distribution of Your modifications, or
      for any such Derivative Works as a whole, provided Your use,
      reproduction, and distribution of the Work otherwise complies with
      the conditions stated in this License.

   5. Submission of Contributions. Unless You explicitly state otherwise,
      any Contribution intentionally submitted for inclusion in the Work
      by You to the Licensor shall be under the terms and conditions of
      this License, without any additional terms or conditions.
      Notwithstanding the above, nothing herein shall supersede or modify
      the terms of any separate license agreement you may have executed
      with Licensor regarding such Contributions.

   6. Trademarks. This License does not grant permission to use the trade
      names, trademarks, service marks, or product names of the Licensor,
      except as required for reasonable and customary use in describing the
      origin of the Work and reproducing the content of the NOTICE file.

   7. Disclaimer of Warranty. Unless required by applicable law or
      agreed to in writing, Licensor provides the Work (and each
      Contributor provides its Contributions) on an "AS IS" BASIS,
      WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
      implied, including, without limitation, any warranties or conditions
      of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A
      PARTICULAR PURPOSE. You are solely responsible for determining the
      appropriateness of using or redistributing the Work and assume any
      risks associated with Your exercise of permissions under this License.

   8. Limitation of Liability. In no event and under no legal theory,
      whether in tort (including negligence), contract, or otherwise,
      unless required by applicable law (such as deliberate and grossly
      negligent acts) or agreed to in writing, shall any Contributor be
      liable to You for damages, including any direct, indirect, special,
      incidental, or consequential damages of any character arising as a
      result of this License or out of the use or inability to use the
      Work (including but not limited to damages for loss of goodwill,
      work stoppage, computer failure or malfunction, or any and all
      other commercial damages or losses), even if such Contributor
      has been advised of the possibility of such damages.

   9. Accepting Warranty or Additional Liability. While redistributing
      the Work or Derivative Works thereof, You may choose to offer,
      and charge a fee for, acceptance of support, warranty, indemnity,
      or other liability obligations and/or rights consistent with this
      License. However, in accepting such obligations, You may act only
      on Your own behalf and on Your sole responsibility, not on behalf
      of any other Contributor, and only if You agree to indemnify,
      defend, and hold each Contributor harmless for any liability
      incurred by, or claims asserted against, such Contributor by reason
      of your accepting any such warranty or additional liability.

   END OF TERMS AND CONDITIONS

   Copyright 2025 Functional Software, Inc. dba Sentry

   Licensed under the Apache License, Version 2.0 (the "License");
   you may not use this file except in compliance with the License.
   You may obtain a copy of the License at

       http://www.apache.org/licenses/LICENSE-2.0

   Unless required by applicable law or agreed to in writing, software
   distributed under the License is distributed on an "AS IS" BASIS,
   WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   See the License for the specific language governing permissions and
   limitations under the License.

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

Security

What our scanner noticed· Medium risk

References to credential files
Instructions that use the network
Downloads piped into a shell

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

Sentry

Publisher

Sentry (Official)

Source

getsentry/skills · skills/gha-security-review · commit e94f222

Licence

Apache License 2.0 (redistribution allowed)

LICENSE (added by AutoGineer from LICENSE)
ATTRIBUTION.md (written by AutoGineer)

Synced

2026-11-09

AutoGineer is not affiliated with or endorsed by Sentry or Sentry.

Download ZIP

The ZIP holds the skill’s files, its licence files and an ATTRIBUTION.md. Download gha-security-review.zip