malcontent is software for discovering supply-chain compromises through context, differential analysis, and YARA. Prior to version 1.21.0, malcontent would remove nested archives which failed to extract which could potentially leave malicious content. A better approach is to preserve these archives so that malcontent can attempt a best-effort scan of the archive bytes. Version 1.21.0 fixes the issue.

malcontent could be made to create symlinks outside the intended extraction directory when scanning a specially crafted tar or deb archive. The handleSymlink function received arguments in the wrong order, causing the symlink target to be used as the symlink location. Additionally, symlink targets were not validated to ensure they resolved within the extraction directory.

Fixes: - Swap handleSymlink arguments; validate symlink location - Validate symlink targets resolve within extraction directory

Acknowledgements

Thank you to Oleh Konko from 1seal for discovering and reporting this issue.