SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityModified

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.

HIGH 7.5EPSS 16.1%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 16.1%, higher than 97% of all known CVEs. Patch or mitigate before the next change window.

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.

CVSS 3.1
7.5 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS
16.11% probability · 97th percentile
CISA KEV
Not listed
Weakness
CWE-617
Affected
isc/bind
Source
security-officer@isc.org

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.