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

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.

Published: 2023-01-26 Last update: 2026-06-17 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2022-3924 is rated Moderate Risk (63.3/100): CVSS High severity, with high exploitation likelihood (EPSS 15.99%, 96th percentile). EPSS ranks this CVE among the most likely to be exploited in the near term. High exploitation likelihood—assess exposure and prioritize remediation.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2022-3924

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-28 16.45% 15.99% -0.46%
2 2026-06-24 17.27% 16.45% -0.82%
3 2026-06-18 — 17.27% —

Full EPSS history (22 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2022-3924

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]
7.5 3.1 HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:N)
Doesn’t really leak secrets in a meaningful way.
Integrity (I:N)
Data isn’t meaningfully altered or forged.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 3.9 3.6 [email protected]

Weakness enumeration for CVE-2022-3924

OS Trackers for CVE-2022-3924

vendor priority summary link
alpine — CVE-2022-3924: 1 source package rows (bind); 54 state rows across 7 repos (3.17-main, 3.18-main, 3.19-main, 3.20-main, 3.21-main, 3.22-main, edge-main); fixed 7, open 47. https://security.alpinelinux.org/vuln/CVE-2022-3924
debian not yet assigned CVE-2022-3924 not yet assigned priority: Debian including 1 source packages (bind9), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2022-3924
redhat medium — https://access.redhat.com/security/cve/CVE-2022-3924
suse high CVE-2022-3924 severity important: SUSE including 306 source package names (amazon/suse-sles-15-sp1-chost-byos-v20210304-hvm-ssd-x86_64, amazon/suse-sles-15-sp1-chost-byos-v20220127-hvm-ssd-x86_64, …), 755 product×package rows across 120 product lines (Image SLES15-SP4, Image SLES15-SP4-Azure-Basic, … (120 product lines)): Known Not Affected 320, Fixed 294, Known Affected 141. https://www.suse.com/security/cve/CVE-2022-3924/
ubuntu medium CVE-2022-3924 medium priority: Ubuntu including 2 source packages (bind9, isc-dhcp), 16 status rows across 8 suites (bionic, focal, jammy, kinetic, lunar, trusty, upstream, xenial): not-affected 11, released 4, needs-triage 1. https://ubuntu.com/security/CVE-2022-3924

Affected software / configurations for CVE-2022-3924

Vendor Product Version Raw CPE
isc bind >= 9.16.12, < 9.16.37 cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*
isc bind >= 9.18.0, < 9.18.11 cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*
isc bind >= 9.19.0, < 9.19.9 cpe:2.3:a:isc:bind:*:*:*:*:-:*:*:*
isc bind 9.16.12 cpe:2.3:a:isc:bind:9.16.12:s1:*:*:supported_preview:*:*:*
isc bind 9.16.13 cpe:2.3:a:isc:bind:9.16.13:s1:*:*:supported_preview:*:*:*
isc bind 9.16.14 cpe:2.3:a:isc:bind:9.16.14:s1:*:*:supported_preview:*:*:*
isc bind 9.16.21 cpe:2.3:a:isc:bind:9.16.21:s1:*:*:supported_preview:*:*:*
isc bind 9.16.32 cpe:2.3:a:isc:bind:9.16.32:s1:*:*:supported_preview:*:*:*
isc bind 9.16.36 cpe:2.3:a:isc:bind:9.16.36:s1:*:*:supported_preview:*:*:*

References for CVE-2022-3924

URL Tags
https://kb.isc.org/docs/cve-2022-3924 Vendor Advisory
cvelogic Threat Intelligence