Description

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.

Classification

CVE ID: CVE-2023-2828

CVSS Base Severity: HIGH

CVSS Base Score: 7.5

Affected Products

Vendor: ISC

Product: BIND 9

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.05% (probability of being exploited)

EPSS Percentile: 22.89% (scored less or equal to compared to others)

EPSS Date: 2025-02-03 (when was this score calculated)

References

https://kb.isc.org/docs/cve-2023-2828
http://www.openwall.com/lists/oss-security/2023/06/21/6
https://lists.fedoraproject.org/archives/list/[email protected]/message/U3K6AJK7RRSR53HRF5GGKPA6PDUDWOD2/
https://www.debian.org/security/2023/dsa-5439
https://lists.fedoraproject.org/archives/list/[email protected]/message/SEFCEVCTYEMKTWA7V7EYPI5YQQ4JWDLI/
https://security.netapp.com/advisory/ntap-20230703-0010/
https://lists.debian.org/debian-lts-announce/2023/07/msg00021.html

Timeline