CVE-2019-8320

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.

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