Integer underflow in MaraDNS - CVE-2023-31137
Published: May 30, 2023 / Updated: April 28, 2026
Vulnerability identifier: #VU76669
CSH Severity: Medium
CVSS v4: 8.7 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
CVE-ID: CVE-2023-31137
CWE-ID: CWE-191
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vulnerability details
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to integer underflow when handling a DNS packet with an Answer RR of qtype 16 (TXT record) and any qclass. A remote attacker can send a specially crafted request to the server, trigger an integer underflow and perform a denial of service (DoS) attack.
Affected software
MaraDNS
Debian Linux
Ubuntu
Fedora
maradns-zoneserver (Ubuntu package)
maradns-deadwood (Ubuntu package)
duende (Ubuntu package)
maradns (Ubuntu package)
maradns (Debian package)
maradns
Debian Linux
Ubuntu
Fedora
maradns-zoneserver (Ubuntu package)
maradns-deadwood (Ubuntu package)
duende (Ubuntu package)
maradns (Ubuntu package)
maradns (Debian package)
maradns
How to mitigate CVE-2023-31137
Install updates from vendor's website.
MaraDNS - update to 3.5.0025
maradns-zoneserver (Ubuntu package) - addressed in versions Ubuntu Pro, 2.0.13-1.4+deb11u1build0.20.04.1, 2.0.13-1.4+deb11u1build0.22.04.1, 2.0.13-1.4+deb11u1build0.23.04.1
maradns-deadwood (Ubuntu package) - addressed in versions Ubuntu Pro, 2.0.13-1.4+deb11u1build0.20.04.1, 2.0.13-1.4+deb11u1build0.22.04.1, 2.0.13-1.4+deb11u1build0.23.04.1
duende (Ubuntu package) - addressed in versions Ubuntu Pro, 2.0.13-1.4+deb11u1build0.20.04.1, 2.0.13-1.4+deb11u1build0.22.04.1, 2.0.13-1.4+deb11u1build0.23.04.1
maradns (Ubuntu package) - addressed in versions Ubuntu Pro, 2.0.13-1.4+deb11u1build0.20.04.1, 2.0.13-1.4+deb11u1build0.22.04.1, 2.0.13-1.4+deb11u1build0.23.04.1
maradns (Debian package) - update to 2.0.13-1.4+deb11u1
maradns - addressed in versions 3.5.0036-1.fc37, 3.5.0036-1.fc38, 3.5.0036-1.fc39
maradns-zoneserver (Ubuntu package) - addressed in versions Ubuntu Pro, 2.0.13-1.4+deb11u1build0.20.04.1, 2.0.13-1.4+deb11u1build0.22.04.1, 2.0.13-1.4+deb11u1build0.23.04.1
maradns-deadwood (Ubuntu package) - addressed in versions Ubuntu Pro, 2.0.13-1.4+deb11u1build0.20.04.1, 2.0.13-1.4+deb11u1build0.22.04.1, 2.0.13-1.4+deb11u1build0.23.04.1
duende (Ubuntu package) - addressed in versions Ubuntu Pro, 2.0.13-1.4+deb11u1build0.20.04.1, 2.0.13-1.4+deb11u1build0.22.04.1, 2.0.13-1.4+deb11u1build0.23.04.1
maradns (Ubuntu package) - addressed in versions Ubuntu Pro, 2.0.13-1.4+deb11u1build0.20.04.1, 2.0.13-1.4+deb11u1build0.22.04.1, 2.0.13-1.4+deb11u1build0.23.04.1
maradns (Debian package) - update to 2.0.13-1.4+deb11u1
maradns - addressed in versions 3.5.0036-1.fc37, 3.5.0036-1.fc38, 3.5.0036-1.fc39
External References
- https://github.com/samboy/MaraDNS/security/advisories/GHSA-58m7-826v-9c3c
- https://github.com/samboy/MaraDNS/commit/bab062bde40b2ae8a91eecd522e84d8b993bab58
- https://github.com/samboy/MaraDNS/blob/08b21ea20d80cedcb74aa8f14979ec7c61846663/dns/Decompress.c#L886
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/NB7LDZM5AGWC5BHHQHW6CP5OFNBBKFOQ/
- https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/3VSMLJX25MXGQ6A7UPOGK7VPUVDESPHL/