Arbitrary command injection in embano1/wip

Vulnerability Description

`embano1/wip` is a GitHub Action written in Bash. Prior to version 2, the `embano1/wip` action uses the `github.event.pull_request.title` parameter in an insecure way. The title parameter is used in a run statement - resulting in a command injection vulnerability due to string interpolation. This vulnerability can be triggered by any user on GitHub. They just need to create a pull request with a commit message containing an exploit. (Note that first-time PR requests will not be run - but the attacker can submit a valid PR before submitting an invalid PR). The commit can be genuine, but the commit message can be malicious. This can be used to execute code on the GitHub runners and can be used to exfiltrate any secrets used in the CI pipeline, including repository tokens. Version 2 has a fix for this issue.

References

• https://github.com/embano1/wip/security/advisories/GHSA-rg3q-prf8-qxmp
• https://github.com/embano1/wip/commit/c25450f77ed02c20d00b76ee3b33ff43838739a2
• https://securitylab.github.com/research/github-actions-untrusted-input/