RAR, UnRAR: Arbitrary File Overwrite

Background

RAR and UnRAR provide command line interfaces for compressing and decompressing RAR files.

Description

Due to an error in the validation of symbolic links within archives, RAR and UnRAR can potentially write files to a directory which is outside of the intended unpack directory.

Impact

If the user running RAR or UnRAR extracts a malicious archive, the archive could overwrite a file such as the user’s shell initialization scripts, potentially resulting in arbitrary code execution in the context of that user.

Workaround

There is no known workaround at this time.

Resolution

All RAR users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=app-arch/rar-6.23"

All UnRAR users should upgrade to the latest version:

 # emerge --sync
 # emerge --ask --oneshot --verbose ">=app-arch/unrar-6.2.10"