Vulnerability in Isc Bind

CVE-2022-3924

This issue can affect BIND 9 resolvers with `stale-answer-enable yes;` that also make use of the option `stale-answer-client-timeout`, configured with a value greater than zero. If the resolver receives many queries that require recursion, there will be a corresponding increase in the number of clients that are waiting for recursion to complete. If there are sufficient clients already waiting when a new client query is received so that it is necessary to SERVFAIL the longest waiting client (see BIND 9 ARM `recursive-clients` limit and soft quota), then it is possible for a race to occur between providing a stale answer to this older client and sending an early timeout SERVFAIL, which may cause an assertion failure. This issue affects BIND 9 versions 9.16.12 through 9.16.36, 9.18.0 through 9.18.10, 9.19.0 through 9.19.8, and 9.16.12-S1 through 9.16.36-S1.

EPSS: 0.161 (96.6th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

  • Isc Bind — versions 9.16.12, 9.16.13, 9.16.14
  • Isc Bind 9 — versions 9.16.12, 9.18.0, 9.19.0

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2022-3924?
CVE-2022-3924 is a high-severity vulnerability in Isc Bind, classified under Reachable Assertion. CVSS score: 7.5/10. Published 2023-01-26.
How severe is CVE-2022-3924?
High severity. CVSS v3 base score is 7.5 out of 10.
Is CVE-2022-3924 known to be exploited?
3 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.