Description
The tcp_request function in Dnsmasq before 2.73rc4 does not properly handle the return value of the setup_reply function, which allows remote attackers to read process memory and cause a denial of service (out-of-bounds read and crash) via a malformed DNS request.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | dnsmasq | 2.72-3.1 | — |
| Debian 13 | dnsmasq | 2.72-3.1 | — |
| Debian 12 | dnsmasq | 2.72-3.1 | — |
| Debian 8 | dnsmasq | 2.72-3+deb8u1 | DSA-3251-1 |
| Debian 7 | dnsmasq | 2.62-3+deb7u2 | DSA-3251-1 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 6.0 | dnsmasq | 2.55-2+deb6u1 | DLA-225-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | dnsmasq | 2.68-1ubuntu0.1 | USN-2593-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 | dnsmasq | 2.71-4.1 | SUSE-SU-2017:2616-1, SUSE-SU-2015:0979-1 |
| SLES 11 SP4 | dnsmasq | 2.78-0.17.5.1 | SUSE-SU-2017:2619-1 |
| SLES 11 SP3 | dnsmasq | 2.78-0.16.5.1 | SUSE-SU-2017:2617-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 | dnsmasq | 2.71-4.1 | SUSE-SU-2015:0979-1 |
| SLES for SAP 11 SP4 | dnsmasq | 2.78-0.17.5.1 | SUSE-SU-2017:2619-1 |
| SUSE Linux Enterprise Point of Sale 11 SP3 | dnsmasq | 2.78-0.16.5.1 | SUSE-SU-2017:2617-1 |
| SUSE Cloud Compute Node for SUSE Linux Enterprise 12 | dnsmasq | 2.71-4.1 | SUSE-SU-2015:0979-2 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | dnsmasq | 2.76-1.3 | openSUSE-SU-2024:10195-1 |
Advisories 9
- DLA-225-1 dnsmasq - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3251-1 dnsmasq - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-2593-1 dnsmasq vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2017:2617-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:2619-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:0979-2 Security update for dnsmasq SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2015:0979-1 Security update for dnsmasq SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2024:10195-1 dnsmasq-2.76-1.3 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2017:2616-1 Security update for dnsmasq SUSE / openSUSE Security Updates · May 2, 2025
References
- DSA-3251 vendor-advisory
- [Dnsmasq-discuss] 20150407 dnsmsaq potential vulnerability mailing-list
- openSUSE-SU-2015:0857 vendor-advisory
- http://thekelleys.org.uk/gitweb/?p=dnsmasq.git%3Ba=commitdiff%3Bh=ad4a8ff7d9097008d7623df8543df435bfddeac8
- http://www.oracle.com/technetwork/topics/security/bulletinjul2015-2511963.html
- USN-2593-1 vendor-advisory
- GLSA-201512-01 vendor-advisory
- [Dnsmasq-discuss] 20150407 dnsmsaq potential vulnerability mailing-list
- 1032195 vdb-entry
- 74452 vdb-entry
- 20150423 Dnsmasq 2.72 Unchecked returned value mailing-list