Smudge and clean filters are Git features that automatically process files during check-in (clean) and check-out (smudge) operations. Clean filters modify files before they are stored in the repository, while smudge filters modify files as they are retrieved. These filters are often used for tasks like formatting code or handling large files. However, if misconfigured or exploited, they can be abused to execute malicious scripts on a user's system during repository operations, posing a significant security risk. Proper configuration and review of filter scripts are essential to prevent potential cyberattacks.