CVE-2023-26485

{"id": "CVE-2023-26485", "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "nvd@nist.gov", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 7.5, "attackVector": "NETWORK", "baseSeverity": "HIGH", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 3.9}, {"type": "Secondary", "source": "security-advisories@github.com", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 5.3, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "LOW", "privilegesRequired": "NONE", "confidentialityImpact": "NONE"}, "impactScore": 1.4, "exploitabilityScore": 3.9}]}, "published": "2023-03-31T23:15:07.250", "references": [{"url": "https://github.com/github/cmark-gfm/commit/07a66c9bc341f902878e37d7da8647d6ef150987", "tags": ["Patch"], "source": "security-advisories@github.com"}, {"url": "https://github.com/github/cmark-gfm/security/advisories/GHSA-r8vr-c48j-fcc5", "tags": ["Exploit", "Vendor Advisory"], "source": "security-advisories@github.com"}], "vulnStatus": "Modified", "weaknesses": [{"type": "Primary", "source": "security-advisories@github.com", "description": [{"lang": "en", "value": "CWE-400"}, {"lang": "en", "value": "CWE-407"}]}], "descriptions": [{"lang": "en", "value": "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.\n\n\n\n\n### Impact\n\nA polynomial time complexity issue in cmark-gfm may lead to unbounded resource exhaustion and subsequent denial of service.\n\n### Proof of concept\n\n```\n$ ~/cmark-gfm$ python3 -c 'pad = \"_\" * 100000; print(pad + \".\" + pad, end=\"\")' | time ./build/src/cmark-gfm --to plaintext\n```\n\nIncreasing the number 10000 in the above commands causes the running time to increase quadratically.\n\n### Patches\n\nThis vulnerability have been patched in 0.29.0.gfm.10.\n\n### Note on cmark and cmark-gfm\n\nXXX: TBD\n\n[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`. \n\n### Credit\n\nWe would like to thank @gravypod for reporting this vulnerability.\n\n### References\n\nhttps://en.wikipedia.org/wiki/Time_complexity\n\n### For more information\n\nIf you have any questions or comments about this advisory:\n\n* Open an issue in [github/cmark-gfm](https://github.com/github/cmark-gfm)\n"}], "lastModified": "2023-11-07T04:09:36.790", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:a:github:cmark-gfm:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "E3CE1A70-0583-4858-9DA3-7A4E9717FE3A", "versionEndExcluding": "0.29.0.gfm.10"}], "operator": "OR"}]}], "sourceIdentifier": "security-advisories@github.com"}