mholt/archiver

A Path Traversal "Zip Slip" vulnerability has been identified in mholt/archiver in Go. This vulnerability allows using a crafted ZIP file containing path traversal symlinks to create or overwrite files with the user's privileges or application utilizing the library. When using the archiver.Unarchive functionality with ZIP files, like this: archiver.Unarchive(zipFile, outputDir),  A crafted ZIP file can be extracted in such a way that it writes files to the affected system with the same privileges as the application executing this vulnerable functionality. Consequently, sensitive files may be overwritten, potentially leading to privilege escalation, code execution, and other severe outcomes in some cases. It's worth noting that a similar vulnerability was found in TAR files (CVE-2024-0406). Although a fix was implemented, it hasn't been officially released, and the affected project has since been deprecated. The successor to mholt/archiver is a new project called mholt/archives, and its initial release (v0.1.0) removes the Unarchive() functionality.

All versions of archiver allow attacker to perform a Zip Slip attack via the "unarchive" functions. It is exploited using a specially crafted zip archive, that holds path traversal filenames. When exploited, a filename in a malicious archive is concatenated to the target extraction directory, which results in the final path ending up outside of the target folder. For instance, a zip may hold a file with a "../../file.exe" location and thus break out of the target folder. If an executable or a configuration file is overwritten with a file containing malicious code, the problem can turn into an arbitrary code execution issue quite easily.

mholt/archiver golang package before e4ef56d48eb029648b0e895bb0b6a393ef0829c3 is vulnerable to directory traversal, allowing attackers to write to arbitrary files via a ../ (dot dot slash) in an archive entry that is mishandled during extraction. This vulnerability is also known as 'Zip-Slip'.