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HIGH7.4

GHSA-5x32-c9mf-49cc

RubyGems Delete directory using symlink when decompressing tar

Quick fix

GHSA-5x32-c9mf-49cc — rubygems-update: upgrade to the fixed version with the command below.

bundle update rubygems-update

Details

A Directory Traversal issue was discovered in RubyGems 2.7.6 and later through 3.0.2. Before making new directories or touching files (which now include path-checking code for symlinks), it would delete the target destination. If that destination was hidden behind a symlink, a malicious gem could delete arbitrary files on the user's machine, presuming the attacker could guess at paths. Given how frequently gem is run as sudo, and how predictable paths are on modern systems (/tmp, /usr, etc.), this could likely lead to data loss or an unusable system.

Are you affected?

Enter the version of the package you're using.

Affected packages

RubyGems/rubygems-update
Introduced in: 2.7.6Fixed in: 2.7.9
Fixbundle update rubygems-update
RubyGems/rubygems-update
Introduced in: 3.0.0Fixed in: 3.0.3
Fixbundle update rubygems-update

References