CVE-2022-3924

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.

How to fix CVE-2022-3924

To remediate CVE-2022-3924, upgrade the affected package to a fixed version below.

• —upgrade to 9.16.37-r0 or later
• —upgrade to 1:9.16.37-1~deb11u1 or later

Is CVE-2022-3924 being exploited?

Low — EPSS is 2.8%, meaning exploitation activity has not been observed at scale.

Affected packages (2)

• from 0, < 9.16.37-r0
• from 0, < 1:9.16.37-1~deb11u1

CVSS scores

References (2)

• ADVISORYsecurity.alpinelinux.org/vuln/CVE-2022-3924
• ADVISORYsecurity-tracker.debian.org/tracker/CVE-2022-3924