Resource Exhaustion Affecting ruby-commonmarker package, versions *


Severity

Recommended
low

Based on Debian security rating.

Threat Intelligence

EPSS
0.09% (42nd percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-DEBIAN11-RUBYCOMMONMARKER-5417212
  • published11 Apr 2023
  • disclosed31 Mar 2023

Introduced: 31 Mar 2023

CVE-2023-26485  (opens in a new tab)
CWE-400  (opens in a new tab)
CWE-407  (opens in a new tab)

How to fix?

There is no fixed version for Debian:11 ruby-commonmarker.

NVD Description

Note: Versions mentioned in the description apply only to the upstream ruby-commonmarker package and not the ruby-commonmarker package as distributed by Debian. See How to fix? for Debian:11 relevant fixed versions and status.

cmark-gfm is GitHub's fork of cmark, a CommonMark parsing and rendering library and program in C. A polynomial time complexity issue in cmark-gfm may lead to unbounded resource exhaustion and subsequent denial of service. This CVE covers quadratic complexity issues when parsing text which leads with either large numbers of _ characters. This issue has been addressed in version 0.29.0.gfm.10. Users are advised to upgrade. Users unable to upgrade should validate that their input comes from trusted sources.

Impact

A polynomial time complexity issue in cmark-gfm may lead to unbounded resource exhaustion and subsequent denial of service.

Proof of concept

$ ~/cmark-gfm$ python3 -c 'pad = "_" * 100000; print(pad + "." + pad, end="")' | time ./build/src/cmark-gfm --to plaintext

Increasing the number 10000 in the above commands causes the running time to increase quadratically.

Patches

This vulnerability have been patched in 0.29.0.gfm.10.

Note on cmark and cmark-gfm

XXX: TBD

cmark-gfm is a fork of cmark that adds the GitHub Flavored Markdown extensions. The two codebases have diverged over time, but share a common core. These bugs affect both cmark and cmark-gfm.

Credit

We would like to thank @gravypod for reporting this vulnerability.

References

https://en.wikipedia.org/wiki/Time_complexity

For more information

If you have any questions or comments about this advisory:

CVSS Scores

version 3.1