CVE-2021-45955
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.
Does this matter?
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.
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
- CVSS 3.1
- 9.8 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 2.60% probability · 85th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-787
- Affected
- thekelleys/dnsmasq
- Source
- cve@mitre.org
EPSS 2.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35898Exploit, Issue Tracking, Third Party Advisory
- https://github.com/google/oss-fuzz-vulns/blob/main/vulns/dnsmasq/OSV-2021-932.yamlThird Party Advisory
- https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016162.htmlMailing List, Third Party Advisory
- https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016164.htmlMailing List, Third Party Advisory
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35898Exploit, Issue Tracking, Third Party Advisory
- https://github.com/google/oss-fuzz-vulns/blob/main/vulns/dnsmasq/OSV-2021-932.yamlThird Party Advisory
- https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016162.htmlMailing List, Third Party Advisory
- https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016164.htmlMailing List, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.