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](https://github.com/github/cmark-gfm) is a fork of [cmark](https://github.com/commonmark/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: * Open an issue in [github/cmark-gfm](https://github.com/github/cmark-gfm)
Find out more about CVE-2023-26485 from the MITRE-CVE dictionary and NIST NVD
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| Product Name | Status | Defect | Fixed | Downloads |
|---|---|---|---|---|
| Linux | ||||
| Wind River Linux LTS 17 | Not Vulnerable | -- | -- | -- |
| Wind River Linux 8 | Not Vulnerable | -- | -- | -- |
| Wind River Linux 9 | Not Vulnerable | -- | -- | -- |
| Wind River Linux 7 | Not Vulnerable | -- | -- | -- |
| Wind River Linux LTS 21 | Not Vulnerable | -- | -- | -- |
| Wind River Linux LTS 22 | Not Vulnerable | -- | -- | -- |
| Wind River Linux LTS 18 | Not Vulnerable | -- | -- | -- |
| Wind River Linux LTS 19 | Not Vulnerable | -- | -- | -- |
| Wind River Linux CD release | Not Vulnerable | -- | -- | -- |
| Wind River Linux 6 | Not Vulnerable | -- | -- | -- |
| Wind River Linux LTS 23 | Not Vulnerable | -- | -- | -- |
| VxWorks | ||||
| VxWorks 7 | Not Vulnerable | -- | -- | -- |
| VxWorks 6.9 | Not Vulnerable | -- | -- | -- |
| Helix Virtualization Platform Cert Edition | ||||
| Helix Virtualization Platform Cert Edition | Not Vulnerable | -- | -- | -- |
| Product Name | Status | Defect | Fixed | Downloads |
|---|
