Directory Traversal Affecting rubygem20-psych package, versions <0:2.0.0-1.32.amzn1
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-AMZN201803-RUBYGEM20PSYCH-1718713
- published27 Sept 2021
- disclosed6 Jun 2019
Introduced: 6 Jun 2019
CVE-2019-8320 (opens in a new tab)How to fix?
Upgrade Amazon-Linux:2018.03 rubygem20-psych to version 0:2.0.0-1.32.amzn1 or higher.
This issue was patched in ALAS-2019-1255.
NVD Description
Note: Versions mentioned in the description apply only to the upstream rubygem20-psych package and not the rubygem20-psych package as distributed by Amazon-Linux.
See How to fix? for Amazon-Linux:2018.03 relevant fixed versions and status.
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.
References
- https://blog.rubygems.org/2019/03/05/security-advisories-2019-03.html
- http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2019-8320
- https://hackerone.com/reports/317321
- https://lists.debian.org/debian-lts-announce/2020/08/msg00027.html
- https://access.redhat.com/errata/RHSA-2019:1429
- http://lists.opensuse.org/opensuse-security-announce/2019-07/msg00036.html