The workflow ran whenever someone opened a GitHub issue and used the issue title as part of a shell command. A change introduced in PR#1218 altered the way this input was handled, allowing an attacker to inject and execute their own commands through the workflow, the researchers explained.
The workflow also contained a protection designed to prevent exploitation by untrusted users. But that check was ineffective because it was built for a pull request, but the exploit involved handling “issues”. Consequently, the check did not work as intended, allowing any GitHub user to get past it.
The vulnerability went live on June 18, when PR#1218 was merged. Wiz said GitHub Advanced Security had scanned the final revision and extracted the vulnerable workflow but failed to flag the injection.
