Monkeytype is vulnerable to Poisoned Pipeline Execution through Code Injection in its `ci-failure-comment.yml` GitHub Workflow, enabling attackers to gain `pull-requests` write access.

Vulnerability Description

Monkeytype is a minimalistic and customizable typing test. Monkeytype is vulnerable to Poisoned Pipeline Execution through Code Injection in its ci-failure-comment.yml GitHub Workflow, enabling attackers to gain pull-requests write access. The ci-failure-comment.yml workflow is triggered when the Monkey CI workflow completes. When it runs, it will download an artifact uploaded by the triggering workflow and assign the contents of ./pr_num/pr_num.txt artifact to the steps.pr_num_reader.outputs.content WorkFlow variable. It is not validated that the variable is actually a number and later it is interpolated into a JS script allowing an attacker to change the code to be executed. This issue leads to pull-requests write access. This vulnerability is fixed in 24.30.0.

References

• https://github.com/monkeytypegame/monkeytype/security/advisories/GHSA-wcjf-5464-4wq9
• https://github.com/monkeytypegame/monkeytype/commit/29627fd0d5f152e2da59671987090ea0a5c29874
• https://securitylab.github.com/advisories/GHSL-2024-167_monkeytype