VulnerabilityModified

CVE-2024-42491

Prior to versions 18.24.3, 20.9.3, and 21.4.3 of Asterisk and versions 18.9-cert12 and 20.7-cert2 of certified-asterisk, if Asterisk attempts to send a SIP request to a URI whose host portion starts with `.1` or `[.1]`, and res_resolver_unbound is…

MEDIUM 5.7EPSS 0.58%

Does this matter?

Lower severity and a low EPSS score (0.58%). Track it; it rarely justifies an emergency change on its own.

Description

Asterisk is an open-source private branch exchange (PBX). Prior to versions 18.24.3, 20.9.3, and 21.4.3 of Asterisk and versions 18.9-cert12 and 20.7-cert2 of certified-asterisk, if Asterisk attempts to send a SIP request to a URI whose host portion starts with `.1` or `[.1]`, and res_resolver_unbound is loaded, Asterisk will crash with a SEGV. To receive a patch, users should upgrade to one of the following versions: 18.24.3, 20.9.3, 21.4.3, certified-18.9-cert12, certified-20.7-cert2. Two workarounds are available. Disable res_resolver_unbound by setting `noload = res_resolver_unbound.so` in modules.conf, or set `rewrite_contact = yes` on all PJSIP endpoints. NOTE: This may not be appropriate for all Asterisk configurations.

CVSS 3.1: 5.7 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
EPSS: 0.58% probability · 48th percentile
Public exploits: None in Exploit-DB
CISA KEV: Not listed
Weakness: CWE-252, CWE-476
Affected: sangoma/asterisk · sangoma/certified asterisk
Source: security-advisories@github.com

EPSS trend

EPSS 0.6% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

References

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.