CVE catalog
CVE-2020-25682
dnsmasq: CVE-2020-25682
- Severity
- High · CVSS 8.1
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H - Published
- Source
- [NVD] · [CVE record]
- EPSS
- 75.07% · Oct 25, 2026
A flaw was found in dnsmasq before 2.83. A buffer overflow vulnerability was discovered in the way dnsmasq extract names from DNS packets before validating them with DNSSEC data. An attacker on the network, who can create valid DNS replies, could use this flaw to cause an overflow with arbitrary data in a heap-allocated memory, possibly executing code on the machine. The flaw is in the rfc1035.c:extract_name() function, which writes data to the memory pointed by name assuming MAXDNAME*2 bytes are available in the buffer. However, in some code execution paths, it is possible extract_name() gets passed an offset from the base buffer, thus reducing, in practice, the number of available bytes that can be written in the buffer. The highest threat from this vulnerability is to data confidentiality and integrity as well as 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-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.11 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.12 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.13 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.14 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.15 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.16 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.17 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.18 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.19 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.20 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.21 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.22 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.23 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Alpine | dnsmasq | apk | 3.24 | 2.83-r0 | Not reported | ALPINE-CVE-2020-25682 | Not reported |
| Ubuntu | dnsmasq | deb | 16.04 | 2.75-1ubuntu0.16.04.7 | Not reported | UBUNTU-CVE-2020-25682 | Not reported |
| Ubuntu | dnsmasq | deb | 18.04 | 2.79-1ubuntu0.2 | Not reported | UBUNTU-CVE-2020-25682 | Not reported |
| Ubuntu | dnsmasq | deb | 20.04 | 2.80-1.1ubuntu1.2 | Not reported | UBUNTU-CVE-2020-25682 | 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-2020-25682]
- [https://osv.dev/vulnerability/DEBIAN-CVE-2020-25682]
- [https://osv.dev/vulnerability/UBUNTU-CVE-2020-25682]
- [https://security-tracker.debian.org/tracker/CVE-2020-25682]
- [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]