CVE catalog
CVE-2020-25687
dnsmasq: CVE-2020-25687
- Severity
- Medium · CVSS 5.9
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 89.28% · Oct 25, 2026
A flaw was found in dnsmasq before version 2.83. A heap-based buffer overflow was discovered in dnsmasq when DNSSEC is enabled and before it validates the received DNS entries. This flaw allows a remote attacker, who can create valid DNS replies, to cause an overflow in a heap-allocated memory. This flaw is caused by the lack of length checks in rfc1035.c:extract_name(), which could be abused to make the code execute memcpy() with a negative size in sort_rrset() and cause a crash in dnsmasq, resulting in a denial of service. The highest threat from this vulnerability is to system availability.
Vulnerable and fixed packages
Distribution-reported package versions and fixes. These do not depend on matching against the OpenFactory package catalog.
| Distribution | Package | Release | Version | Status |
|---|---|---|---|---|
| Debian | dnsmasq | sid | 2.93-3 | fixed |
| Debian | dnsmasq | forky | 2.93-3 | fixed |
| Debian | dnsmasq | trixie | 2.91-1+deb13u2 | fixed |
| Debian | dnsmasq | trixie-security | 2.91-1+deb13u1 | fixed |
| Debian | dnsmasq | bookworm | 2.90-4~deb12u2 | fixed |
| Debian | dnsmasq | bookworm-security | 2.90-4~deb12u2 | fixed |
| Alpine | dnsmasq | 3.10 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.11 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.12 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.13 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.14 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.15 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.16 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.17 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.18 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.19 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.20 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.21 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.22 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.23 | 2.83-r0 | fixed |
| Alpine | dnsmasq | 3.24 | 2.83-r0 | fixed |
| Ubuntu | dnsmasq | 16.04 | 2.75-1 | vulnerable |
| Ubuntu | dnsmasq | 16.04 | 2.75-1ubuntu0.16.04.1 | vulnerable |
| Ubuntu | dnsmasq | 16.04 | 2.75-1ubuntu0.16.04.2 | vulnerable |
| Ubuntu | dnsmasq | 16.04 | 2.75-1ubuntu0.16.04.3 | vulnerable |
| Ubuntu | dnsmasq | 16.04 | 2.75-1ubuntu0.16.04.4 | vulnerable |
| Ubuntu | dnsmasq | 16.04 | 2.75-1ubuntu0.16.04.5 | vulnerable |
| Ubuntu | dnsmasq | 16.04 | 2.75-1ubuntu0.16.04.7 | fixed |
| Ubuntu | dnsmasq | 18.04 | 2.78-1 | vulnerable |
| Ubuntu | dnsmasq | 18.04 | 2.78-3 | vulnerable |
| Ubuntu | dnsmasq | 18.04 | 2.79-1 | vulnerable |
| Ubuntu | dnsmasq | 18.04 | 2.79-1ubuntu0.2 | fixed |
| Ubuntu | dnsmasq | 20.04 | 2.80-1ubuntu2 | vulnerable |
| Ubuntu | dnsmasq | 20.04 | 2.80-1ubuntu4 | vulnerable |
| Ubuntu | dnsmasq | 20.04 | 2.80-1.1ubuntu1 | vulnerable |
| Ubuntu | dnsmasq | 20.04 | 2.80-1.1ubuntu1.2 | fixed |
Fixed-version evidence
| Distribution | Package | Type | Release | Fixed version | Urgency | Origin | Bugs |
|---|---|---|---|---|---|---|---|
| Debian | dnsmasq | source | sid | 2.83-1 | not yet assigned | Not reported | Not reported |
| Debian | dnsmasq | source | forky | 2.83-1 | not yet assigned | Not reported | Not reported |
| Debian | dnsmasq | source | trixie | 2.83-1 | not yet assigned | Not reported | Not reported |
| Debian | dnsmasq | source | bookworm | 2.83-1 | not yet assigned | Not reported | Not reported |
| Alpine | dnsmasq | apk | 3.10 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.11 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.12 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.13 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.14 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.15 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.16 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.17 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.18 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.19 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.20 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.21 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.22 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.23 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Alpine | dnsmasq | apk | 3.24 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25687 | Not reported |
| Ubuntu | dnsmasq | deb | 16.04 | 2.75-1ubuntu0.16.04.7 | Not reported | UBUNTU-CVE-2020-25687 | Not reported |
| Ubuntu | dnsmasq | deb | 18.04 | 2.79-1ubuntu0.2 | Not reported | UBUNTU-CVE-2020-25687 | Not reported |
| Ubuntu | dnsmasq | deb | 20.04 | 2.80-1.1ubuntu1.2 | Not reported | UBUNTU-CVE-2020-25687 | Not reported |
OpenFactory catalog packages
Matching against OpenFactory catalog package versions is in progress.
[Debian 12 (Bookworm)]
- [dnsmasq]Unknown
Details (4)
2.90-4~deb12u2· all · bookwormFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· all · bookwormFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· all · bookworm-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· all · bookworm-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- [dnsmasq-base]Unknown
Source package: [dnsmasq]
Details (4)
2.90-4~deb12u2· amd64 · bookwormFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookwormFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· amd64 · bookworm-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookworm-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- [dnsmasq-base-lua]Unknown
Source package: [dnsmasq]
Details (4)
2.90-4~deb12u2· amd64 · bookwormFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookwormFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· amd64 · bookworm-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookworm-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
- [dnsmasq-utils]Unknown
Source package: [dnsmasq]
Details (4)
2.90-4~deb12u2· amd64 · bookwormFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookwormFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· amd64 · bookworm-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
2.90-4~deb12u2· arm64 · bookworm-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · bookworm; dsa · dnsmasq · debian · 12
[Debian 13 (Trixie)]
- [dnsmasq]Unknown
Details (4)
2.91-1+deb13u1· all · trixieFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· all · trixieFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· all · trixie-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· all · trixie-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
- [dnsmasq-base]Unknown
Source package: [dnsmasq]
Details (4)
2.91-1+deb13u1· amd64 · trixieFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixieFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· amd64 · trixie-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixie-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
- [dnsmasq-base-lua]Unknown
Source package: [dnsmasq]
Details (4)
2.91-1+deb13u1· amd64 · trixieFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixieFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· amd64 · trixie-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixie-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
- [dnsmasq-utils]Unknown
Source package: [dnsmasq]
Details (4)
2.91-1+deb13u1· amd64 · trixieFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixieFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· amd64 · trixie-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
2.91-1+deb13u1· arm64 · trixie-securityFixed · Fixed:
2.83-1dsa · dnsmasq · debian · 13
Observed:
References
- [https://access.redhat.com/errata/RHSA-2021:0150]
- [https://ftp.suse.com/pub/projects/security/csaf/rhsa-2021_0150.json]
- [https://osv.dev/vulnerability/ALPINE-CVE-2020-25687]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2020-25687]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2020-25687]
- [https://security-tracker.debian.org/tracker/CVE-2020-25687]
- [https://wid.cert-bund.de/.well-known/csaf/white/2021/wid-sec-w-2023-2836.json]
[CERT-Bund public advisories] · [Debian Security Tracker] · [FIRST EPSS] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]