CVE-2021-45955
highpriority · track · 40EPSS 0.026 · 85 %ileEURUUSEPSS · scored 2026-10-26
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
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · high–critical · 7.5–9.8
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (6)
Products and version ranges known to be affected.
also known as (4)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (14)
External citations — patches, advisories, analysis.
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35898cnnvd
- https://github.com/google/oss-fuzz-vulns/blob/main/vulns/dnsmasq/OSV-2021-932.yamlcnnvd
- https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016162.htmlcnnvd
- https://lists.thekelleys.org.uk/pipermail/dnsmasq-discuss/2022q1/016164.htmlcnnvd
- https://nvd.nist.gov/vuln/detail/CVE-2021-45955cnnvd
- https://vigilance.fr/vulnerability/Dnsmasq-buffer-overflow-via-resize-packet-37162cnnvd
- https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35898enisa_euvd
- https://github.com/google/oss-fuzz-vulns/blob/main/vulns/dnsmasq/OSV-2021-932.yamlenisa_euvd
Attackers weaponise vulnerabilities like this against internet-exposed services. See what is exposed on your perimeter with a free passive scan.
Free scan