Am Mon, Apr 10, 2023 at 06:11:39PM +0200 schrieb Moritz Mühlenhoff: > Source: python-cmarkgfm > X-Debbugs-CC: [email protected] > 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
This is fixed in the 2014.1.14 upstream release by means of https://github.com/theacodes/cmarkgfm/commit/acf473a51a9dc3a4fd6d6a4b30e4d80c94d91d4a Besides CVE-2023-24824 CVE-2023-26485, this release also fixes: CVE-2023-37463 (no bug), CVE-2023-22486/CVE-2023-22485/CVE-2023-22484/CVE-2023-22483 (#1033111), CVE-2022-39209 (#1034887) Cheers, Moritz
