CVE-2021-45954 json
Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from answer_auth and FuzzAuth).
published 2021-12-31 4 y ago modified 2026-06-17 4 mo ago also EUVD-2021-32661
- cvss
- 9.8
- version 3.1, NVD
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 2.7%
- EPSS 2.7% chance of exploitation in 30 days, percentile 86%
- public exploits
- 0
- none known
Summary
Dnsmasq 2.86 has a heap-based buffer overflow in extract_name (called from answer_auth and FuzzAuth). 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.
Vendor advisories
What the vendors themselves say about their products: affected, fixed or not affected, and what to do.
red hat product security vex CVE-2021-45954 updated cvss 0.0
dnsmasq: a heap-based buffer overflow in extract_name
-
Red Hat Enterprise Linux 6 dnsmasq, dnsmasq-utils Red Hat Enterprise Linux 7 dnsmasq, dnsmasq-utils Red Hat Enterprise Linux 8 dnsmasq, dnsmasq-utils Red Hat Enterprise Linux 9 dnsmasq, dnsmasq-utils Red Hat OpenStack Platform 13 (Queens) dnsmasq-utilsnot affected: vulnerable code not present
Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf
Exploit prediction
2.71% chance of exploitation in the next 30 days, higher than 86% of all scored CVEs (FIRST EPSS, 2026-11-08).
Exploits and checks
- bugs.chromium.org https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=35861 referenced PoC, tagged "exploit" by a source, unverified
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| NVD | 3.1 | 9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
| NVD | 2.0 | 7.5 | AV:N/AC:L/Au:N/C:P/I:P/A:P |
Classification
- Weakness
-
- CWE-787 Out-of-bounds Write
References
-
bugs.chromium.org
/p/oss-fuzz/issues/detail?id=35861
exploit, issue-tracking, third-party-advisory
-
github.com
/google/oss-fuzz-vulns/blob/main/vulns/dnsmasq/OSV-2021-931.yaml
third-party-advisory
-
lists.thekelleys.org.uk
/pipermail/dnsmasq-discuss/2022q1/016162.html
mailing-list, third-party-advisory
-
lists.thekelleys.org.uk
/pipermail/dnsmasq-discuss/2022q1/016164.html
mailing-list, third-party-advisory
Sources
- CVE List CVE-2021-45954
- NVD CVE-2021-45954
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.