Vulnerability · Published Feb 13, 2024 · Assigned by isc

CVE-2023-6516Specific recursive query patterns may lead to an out-of-memory condition

High 7.5

In plain English

A high-severity security flaw in BIND 9 from ISC. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.1% (higher than 66% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High
Exploit odds (30 days)1.1%top 34.2% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

To keep its cache database efficient, `named` running as a recursive resolver occasionally attempts to clean up the database. It uses several methods, including some that are asynchronous: a small chunk of memory pointing to the cache element that can be cleaned up is first allocated and then queued for later processing. It was discovered that if the resolver is continuously processing query patterns triggering this type of cache-database maintenance, `named` may not be able to handle the cleanup events in a timely manner. This in turn enables the list of queued cleanup events to grow infinitely large over time, allowing the configured `max-cache-size` limit to be significantly exceeded. This issue affects BIND 9 versions 9.16.0 through 9.16.45 and 9.16.8-S1 through 9.16.45-S1.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
AlmaLinux:9bind32:9.16.23-14.el9_3.4ALSA-2024:1789
AlmaLinux:9bind32:9.16.23-18.el9_4.1ALSA-2024:2551
AlmaLinux:9bind-chroot32:9.16.23-18.el9_4.1ALSA-2024:2551
AlmaLinux:9bind-chroot32:9.16.23-14.el9_3.4ALSA-2024:1789
AlmaLinux:9bind-devel32:9.16.23-14.el9_3.4ALSA-2024:1789
AlmaLinux:9bind-devel32:9.16.23-18.el9_4.1ALSA-2024:2551
AlmaLinux:9bind-dnssec-doc32:9.16.23-18.el9_4.1ALSA-2024:2551
AlmaLinux:9bind-dnssec-doc32:9.16.23-14.el9_3.4ALSA-2024:1789
AlmaLinux:9bind-dnssec-utils32:9.16.23-18.el9_4.1ALSA-2024:2551
AlmaLinux:9bind-dnssec-utils32:9.16.23-14.el9_3.4ALSA-2024:1789
AlmaLinux:9bind-doc32:9.16.23-14.el9_3.4ALSA-2024:1789
AlmaLinux:9bind-doc32:9.16.23-18.el9_4.1ALSA-2024:2551
AlmaLinux:9bind-dyndb-ldap11.9-9.el9_4.alma.1ALSA-2024:2551
AlmaLinux:9bind-dyndb-ldap11.9-8.el9_3.3.alma.1ALSA-2024:1789
AlmaLinux:9bind-libs32:9.16.23-18.el9_4.1ALSA-2024:2551
AlmaLinux:9bind-libs32:9.16.23-14.el9_3.4ALSA-2024:1789
AlmaLinux:9bind-license32:9.16.23-18.el9_4.1ALSA-2024:2551
AlmaLinux:9bind-license32:9.16.23-14.el9_3.4ALSA-2024:1789
AlmaLinux:9bind-utils32:9.16.23-14.el9_3.4ALSA-2024:1789
AlmaLinux:9bind-utils32:9.16.23-18.el9_4.1ALSA-2024:2551
AlmaLinux:8bind9.1632:9.16.23-0.16.el8_9.2.alma.1ALSA-2024:1781
AlmaLinux:8bind9.16-chroot32:9.16.23-0.16.el8_9.2.alma.1ALSA-2024:1781
AlmaLinux:8bind9.16-devel32:9.16.23-0.16.el8_9.2.alma.1ALSA-2024:1781
AlmaLinux:8bind9.16-dnssec-utils32:9.16.23-0.16.el8_9.2.alma.1ALSA-2024:1781
AlmaLinux:8bind9.16-doc32:9.16.23-0.16.el8_9.2.alma.1ALSA-2024:1781
AlmaLinux:8bind9.16-libs32:9.16.23-0.16.el8_9.2.alma.1ALSA-2024:1781
AlmaLinux:8bind9.16-license32:9.16.23-0.16.el8_9.2.alma.1ALSA-2024:1781
AlmaLinux:8bind9.16-utils32:9.16.23-0.16.el8_9.2.alma.1ALSA-2024:1781
AlmaLinux:9python3-bind32:9.16.23-18.el9_4.1ALSA-2024:2551
AlmaLinux:9python3-bind32:9.16.23-14.el9_3.4ALSA-2024:1789
AlmaLinux:8python3-bind9.1632:9.16.23-0.16.el8_9.2.alma.1ALSA-2024:1781
Alpine:v3.20bind9.18.24-r0ALPINE-CVE-2023-6516
Alpine:v3.21bind9.18.24-r0ALPINE-CVE-2023-6516
Alpine:v3.22bind9.18.24-r0ALPINE-CVE-2023-6516
Alpine:v3.23bind9.18.24-r0ALPINE-CVE-2023-6516
Alpine:v3.24bind9.18.24-r0ALPINE-CVE-2023-6516
Debian:12bind91:9.17.19-1DEBIAN-CVE-2023-6516
Debian:13bind91:9.17.19-1DEBIAN-CVE-2023-6516
Debian:14bind91:9.17.19-1DEBIAN-CVE-2023-6516
Rocky Linux:9bind2:9.16.23-18.el9_4.1RLSA-2024:2551
Rocky Linux:9bind-dyndb-ldap0:11.9-9.el9_4RLSA-2024:2551
Rocky Linux:8bind9.162:9.16.23-0.16.el8_9.2RLSA-2024:1781

Affected products (as reported)

VendorProductVersions
ISC BIND 9 9.16.0 – through 9.16.459.16.8-S1 – through 9.16.45-S1

Weakness: CWE-789 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

References