CVE-2023-2829 Malformed NSEC records can cause named to terminate unexpectedly when synth-from-dnssec is enabled

High 7.5 Published 21 Jun 2023 Updated 13 Feb 2025

Remote attackers can crash the BIND DNS server by sending malformed NSEC records when the synth-from-dnssec option is enabled.

Exploited in the wild: Not known
Login needed: Not needed
Attackable: Over the internet
Victim action needed: Not needed
Fix: Available

What is CVE-2023-2829?

CVE-2023-2829 is a high-severity denial of service vulnerability in Isc Bind, published on 21 Jun 2023. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

A `named` instance configured to run as a DNSSEC-validating recursive resolver with the Aggressive Use of DNSSEC-Validated Cache (RFC 8198) option (`synth-from-dnssec`) enabled can be remotely terminated using a zone with a malformed NSEC record. This issue affects BIND 9 versions 9.16.8-S1 through 9.16.41-S1 and 9.18.11-S1 through 9.18.15-S1.

Which versions are affected by CVE-2023-2829?

It affects 7 products.

Products include Isc Bind, Netapp Active Iq Unified Manager, Netapp H300s Firmware, Netapp H410c Firmware, Netapp H410s Firmware, Netapp H500s Firmware and 1 more.

How do I fix CVE-2023-2829?

Apply the vendor's patch.

Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.

Is CVE-2023-2829 being exploited?

There is no known exploitation of CVE-2023-2829 in the wild and no public exploit code.

All Isc Bind vulnerabilities

Sources

Also known as AZL-27305, GHSA-jhg8-766m-r23j.