Vulnerabilities > CVE-2022-39209 - Algorithmic Complexity vulnerability in multiple products
Attack vector
NETWORK Attack complexity
LOW Privileges required
LOW Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH Summary
cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. In versions prior to 0.29.0.gfm.6 a polynomial time complexity issue in cmark-gfm's autolink extension may lead to unbounded resource exhaustion and subsequent denial of service. Users may verify the patch by running `python3 -c 'print("![l"* 100000 + "\n")' | ./cmark-gfm -e autolink`, which will resource exhaust on unpatched cmark-gfm but render correctly on patched cmark-gfm. This vulnerability has been patched in 0.29.0.gfm.6. Users are advised to upgrade. Users unable to upgrade should disable the use of the autolink extension.
Vulnerable Configurations
Common Weakness Enumeration (CWE)
References
- https://github.com/github/cmark-gfm/security/advisories/GHSA-cgh3-p57x-9q7q
- https://en.wikipedia.org/wiki/Time_complexity
- https://github.com/github/cmark-gfm/commit/9d57d8a23142b316282bdfc954cb0ecda40a8655
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JMGP65NANDVKPDMXMKYO2ZV2H2HZJY4P/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JIUCZN3PEKUCT2JQYQTYOVIJG2KSD6G7/
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/UEAAAI4OULDYQ2TA3HOXH54PC3DCBFZS/