github-actions-injection
GitHub Actions ${{ }} expression injection — attacker-controlled context (issue/PR title, body, branch name, commit message) substituted into run: steps, unsafe pull_request_target + PR-head checkout, GITHUB_TOKEN scope abuse, artifact/cache poisoning, action tag-vs-SHA pinning.
64
76%
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Critical
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tessl review fix ./packages/decepticon/decepticon/skills/standard/exploit/cicd/github-actions-injection/SKILL.mdSecurity
2 findings: 1 critical severity, 1 medium severity. Installing this skill is not recommended: please review these findings carefully if you do intend to do so.
E006: Malicious code pattern detected in skill scripts.
What this means
Detected high-risk code patterns in the skill content — including its prompts, tool definitions, and resources — such as data exfiltration, backdoors, remote code execution, credential theft, system compromise, supply chain attacks, and obfuscation techniques.
Why it was flagged
The document contains explicit, actionable exploit payloads and step-by-step instructions for achieving remote code execution in GitHub Actions, exfiltrating parts of GITHUB_TOKEN, abusing token scopes to push/merge/release, and poisoning artifacts—clear offensive guidance usable for malicious abuse.
W013: Attempt to modify system services in skill instructions.
What this means
The skill prompts the agent to compromise the security or integrity of the user’s machine by modifying system-level services or configurations, such as obtaining elevated privileges, altering startup scripts, or changing system-wide settings.
Why it was flagged
The prompt explicitly instructs how to achieve remote code execution on GitHub Actions runners and includes concrete payloads/commands to exfiltrate GITHUB_TOKEN and modify repository state (push branches, create releases), which directs the agent to compromise the machine state.
Low
Low-risk findings.
1 low severity finding. Worth noting, but not necessarily harmful.
W011: Third-party content exposure detected (indirect prompt injection risk).
What this means
The skill exposes the agent to untrusted, user-generated content from public third-party sources, creating a risk of indirect prompt injection. This includes browsing arbitrary URLs, reading social media posts or forum comments, and analyzing content from unknown websites.
Why it was flagged
The required workflow shown in `SKILL.md` describes a GitHub Actions runtime path where outsider-authored issue/PR/comment/branch text (e.g., `github.event.issue.title` / `.body`) is interpolated into a `run:` shell block via `${{ ... }}`, meaning attacker-controlled free text reaches the runner’s bash/pwsh context.
- Repository
- PurpleAILAB/Decepticon
- Commit
0cf691e
- Audited
- Security analysis
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