Github · Tj-Actions/Verify-Changed-Files · CVE-2023-52137
**Name of the Vulnerable Software and Affected Versions**
tj-actions/verify-changed-files versions prior to 17
**Description**
The tj-actions/verify-changed-files action allows for command injection in changed filenames, allowing an attacker to execute arbitrary code and potentially leak secrets. The verify-changed-files workflow returns the list of files changed within a workflow execution. This could potentially allow filenames that contain special characters such as `;` which can be used by an attacker to take over the GitHub Runner if the output value is used in a raw fashion (thus being directly replaced before execution) inside a `run` block. By running custom commands, an attacker may be able to steal secrets such as `GITHUB TOKEN` if triggered on other events than `pull request`.
**Recommendations**
To resolve the issue, update to version 17 or later, which enables `safe output` by default and returns filename paths escaping special characters for bash environments. As a temporary workaround, consider using environment variables to store unsafe outputs, such as `CHANGED FILES`, to minimize the risk of exploitation. For example:
```yaml
- name: List all changed files tracked and untracked files
env:
CHANGED FILES: ${{ steps.verify-changed-files.outputs.changed files }}
run: |
echo "Changed files: $CHANGED FILES"
```