Path Traversal in Rubygems

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.

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.042 (89.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.4 (High). Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:H.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2019-8320?
CVE-2019-8320 is a high-severity vulnerability in Rubygems, classified under Path Traversal. CVSS score: 7.4/10. Published 2019-06-06.
How severe is CVE-2019-8320?
High severity. CVSS v3 base score is 7.4 out of 10.
Is CVE-2019-8320 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.