Junrar: Path Traversal (Zip-Slip) via Sibling Directory Name Prefix

Summary

A path traversal vulnerability in LocalFolderExtractor allows an attacker to write arbitrary files with attacker-controlled content into sibling directories when a crafted RAR archive is extracted.

Example

Given an extraction directory set to /tmp/extract, a crafted archive with an entry with the filename as ../extract_evil/file.txt would be actually extracted to /tmp/extract_evil/file.txt.

Details

The createDirectory() and createFile() methods inLocalFolderExtractor validate extraction paths using a string prefix.