Description

If the `recursive-clients` quota is reached on a BIND 9 resolver configured with both `stale-answer-enable yes;` and `stale-answer-client-timeout 0;`, a sequence of serve-stale-related lookups could cause `named` to loop and terminate unexpectedly due to a stack overflow.
This issue affects BIND 9 versions 9.16.33 through 9.16.41, 9.18.7 through 9.18.15, 9.16.33-S1 through 9.16.41-S1, and 9.18.11-S1 through 9.18.15-S1.

Classification

CVE ID: CVE-2023-2911

CVSS Base Severity: HIGH

CVSS Base Score: 7.5

Affected Products

Vendor: ISC

Product: BIND 9

Exploit Prediction Scoring System (EPSS)

EPSS Score: 0.1% (probability of being exploited)

EPSS Percentile: 42.47% (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-2023-2911
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/

Timeline