named configured to answer from stale cache may terminate unexpectedly at recursive-clients soft quota
CVE-2022-3924

7.5HIGH

Key Information:

Vendor
Isc
Status
Bind 9
Vendor
CVE Published:
25 January 2023

Badges

👾 Exploit Exists

Summary

The vulnerability in BIND 9 resolvers occurs due to improper handling of client queries when the 'stale-answer-enable' option is activated along with a positive 'stale-answer-client-timeout' setting. When the resolver experiences a high volume of recursive queries, it may need to terminate the longest waiting client in order to serve a new request. This scenario risks a race condition between sending a stale answer and issuing a 'SERVFAIL' response, potentially leading to an assertion failure that disrupts normal operations. Systems running vulnerable versions of BIND 9 should be assessed and updated to mitigate this risk.

Affected Version(s)

BIND 9 9.16.12 <= 9.16.36

BIND 9 9.18.0 <= 9.18.10

BIND 9 9.19.0 <= 9.19.8

References

https://kb.isc.org/docs/cve-2022-3924
vendor-advisory

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

ISC would like to thank Maksym Odinintsev from AWS for bringing this vulnerability to our attention.
.