ISC BIND: Configured to answer from stale cache may terminate unexpectedly at recursive-clients soft quota (CVE-2022-3924)

ISC BIND: Configured to answer from stale cache may terminate unexpectedly at recursive-clients soft quota (CVE-2022-3924)

Severity

8

CVSS

(AV:N/AC:L/Au:N/C:N/I:N/A:C)

Published

01/26/2023

Created

03/08/2023

Added

03/07/2023

Modified

01/28/2025

Description

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.

Solution(s)

• upgrade-isc-bind-latest

References

• https://attackerkb.com/topics/cve-2022-3924
• CVE - 2022-3924
• https://kb.isc.org/v1/docs/cve-2022-3924