{"id":"CVE-2021-45955","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-45955","generatedAt":"2026-10-27T18:48:58.554Z","title":"Dnsmasq 2.86 has a heap-based buffer overflow in resize_packet (called from FuzzResizePacket and fuzz_rfc1035.c) because of the lack of a proper bounds check upon pseudo header re-insertion.","description":"Dnsmasq 2.86 has a heap-based buffer overflow in resize_packet (called from FuzzResizePacket and fuzz_rfc1035.c) because of the lack of a proper bounds check upon pseudo header re-insertion. NOTE: the vendor's position is that CVE-2021-45951 through CVE-2021-45957 \"do not represent real vulnerabilities, to the best of our knowledge.\" However, a contributor states that a security patch (mentioned in 016162.html) is needed","published":"2022-01-01T00:15:09.000Z","lastModified":"2026-06-17T04:14:19.000Z","status":"Modified","sourceIdentifier":"cve@mitre.org","cvss":{"version":"3.1","score":9.8,"severity":"CRITICAL","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-787"],"affected":["thekelleys/dnsmasq"],"epss":{"score":0.02602,"percentile":0.85256,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"high","text":"High impact if exploited, but EPSS currently rates exploitation as unlikely (2.60%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit."},"changes":[],"references":[{"url":"https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35898","tags":["Exploit","Issue Tracking","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://github.com/google/oss-fuzz-vulns/blob/main/vulns/dnsmasq/OSV-2021-932.yaml","tags":["Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016162.html","tags":["Mailing List","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016164.html","tags":["Mailing List","Third Party Advisory"],"source":"cve@mitre.org"},{"url":"https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35898","tags":["Exploit","Issue Tracking","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://github.com/google/oss-fuzz-vulns/blob/main/vulns/dnsmasq/OSV-2021-932.yaml","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016162.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016164.html","tags":["Mailing List","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-45955","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}