Source: python-cmarkgfm X-Debbugs-CC: t...@security.debian.org Severity: important Tags: security
Hi, The following vulnerabilities were published for python-cmarkgfm. CVE-2023-26485[0]: | 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) https://github.com/github/cmark-gfm/security/advisories/GHSA-r8vr-c48j-fcc5 https://github.com/github/cmark-gfm/commit/07a66c9bc341f902878e37d7da8647d6ef150987 CVE-2023-24824[1]: | 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 `>` or `-` | 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. https://github.com/github/cmark-gfm/security/advisories/GHSA-66g8-4hjf-77xh https://github.com/github/cmark-gfm/commit/2300c1bd2c8226108885bf019655c4159cf26b59 If you fix the vulnerabilities please also make sure to include the CVE (Common Vulnerabilities & Exposures) ids in your changelog entry. For further information see: [0] https://security-tracker.debian.org/tracker/CVE-2023-26485 https://www.cve.org/CVERecord?id=CVE-2023-26485 [1] https://security-tracker.debian.org/tracker/CVE-2023-24824 https://www.cve.org/CVERecord?id=CVE-2023-24824 Please adjust the affected versions in the BTS as needed.