Hacker News: Whose code am I running in GitHub Actions?

Mar 25, 2025

—

Source URL: https://alexwlchan.net/2025/github-actions-audit/
Source: Hacker News
Title: Whose code am I running in GitHub Actions?

Feedly Summary: Comments

AI Summary and Description: Yes

Summary: The text discusses a recent security issue with the tj-actions/changed-files GitHub Action, highlighting the risks of mutable Git tags as opposed to immutable commit references in CI/CD processes. It emphasizes the importance of scrutinizing dependencies used in GitHub Actions workflows for potential security vulnerabilities.

Detailed Description:
– **Security Incident**: A recent case where malicious code was inserted into the tj-actions/changed-files GitHub Action, highlighting risks for users of compromised actions.
– **Mutable vs Immutable References**:
– **Mutable Tags**: These can point to different commits at different times, which can lead to unexpected code execution.
– **Immutable References**: These are fixed to a specific commit ID, ensuring consistent behavior and security.
– **Personal Audit**: The author demonstrates how they conduct an analysis of their own workflows by running a shell script to identify all GitHub Actions being used across their repositories.
– **Trust Evaluation**: They evaluate the origins and security practices of the actions being used, distinguishing between well-known organizations and individual developers.
– **Custom Solutions**: A recommendation is made to consider writing custom scripts instead of relying on third-party actions whenever feasible, thereby reducing the risk exposure.
– **Unix Text Processing**: The author provides insights into the practical utility of Unix command-line tools for data processing, which is relevant for managing and auditing CI/CD workflows effectively.

*Key points to consider for professionals in security and compliance*:
– Regularly audit dependencies in CI/CD pipelines to mitigate risks associated with third-party actions.
– Favor immutable references in your workflows for better security control.
– Familiarize yourself with Unix text processing to streamline workflows and enhance your ability to audit configurations efficiently.

.NET 2 2025 5 a Act actions AGI AI analysis and Arize art as audit auditing Behavior being by C CI/CD CIA co code code execution command command-line tool command-line tools compliance compromised Configuration configurations control cross custom solutions D data data processing de demo dependencies developer developers dual e effective efficient end evaluation execution exp for g git GitHub GitHub Action GitHub Actions gs H hack hacker Hacker News high Highlight http HTTPS immutable immutable references in incident insights J k Key l led Li line tools low malicious code man ML mutable tags N news Nix no o of on organization organizations party party actions Pipeline pipelines point potential process processes processing professionals R rate RCE red Risk risks Ro Rust s sec security security and compliance security incident security practices Security Vulnerabilities self shell script side Sig SoC solutions source specific SSE SSO T text the third third-party third-party actions Time to tool tools Tor TP trust trust evaluation UI Unix Unix text processing US use user Users uth V val Valuation vulnerabilities Well Wi workflow workflows x