CVE-2023-2828

Published: 21 June 2023

Every `named` instance configured to run as a recursive resolver maintains a cache database holding the responses to the queries it has recently sent to authoritative servers. The size limit for that cache database can be configured using the `max-cache-size` statement in the configuration file; it defaults to 90% of the total amount of memory available on the host. When the size of the cache reaches 7/8 of the configured limit, a cache-cleaning algorithm starts to remove expired and/or least-recently used RRsets from the cache, to keep memory use below the configured limit. It has been discovered that the effectiveness of the cache-cleaning algorithm used in `named` can be severely diminished by querying the resolver for specific RRsets in a certain order, effectively allowing the configured `max-cache-size` limit to be significantly exceeded. This issue affects BIND 9 versions 9.11.0 through 9.16.41, 9.18.0 through 9.18.15, 9.19.0 through 9.19.13, 9.11.3-S1 through 9.16.41-S1, and 9.18.11-S1 through 9.18.15-S1.

Notes

As of isc-dhcp-4.4.3-1, isc-dhcp vendors bind9 libs

This is unlikely to affect isc-dhcp's use of bind9-libs and the
vendored bind9 libs, marking as negligible

Status

Severity score breakdown

References

• https://kb.isc.org/v1/docs/cve-2023-2828
• https://ubuntu.com/security/notices/USN-6183-1
• https://ubuntu.com/security/notices/USN-6183-2
• https://www.cve.org/CVERecord?id=CVE-2023-2828
• NVD
• Launchpad
• Debian