CVE-2024-42491

A malformed Contact or Record-Route URI in an incoming SIP request can cause Asterisk to crash when res_resolver_unbound is used

Published Sep 5, 2024 CVSS 3.1 · 5.7 Medium EPSS < 1% KEV · Not listed
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.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

Source ID Title
Debian DLA Debian DLA DLA-3925-1 asterisk security update
EUVD EUVD EUVD-2024-39644 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.
History
Type Values Removed Values Added
First Time appeared Sangoma
Sangoma asterisk
Sangoma certified Asterisk
CPEs cpe:2.3:a:sangoma:asterisk:*:*:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:*:*:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:-:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert1-rc1:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert10:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert11:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert1:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert2:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert3:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert4:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert5:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert6:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert7:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert8-rc1:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert8-rc2:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert8:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:18.9:cert9:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:20.7:cert1-rc1:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:20.7:cert1-rc2:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:20.7:cert1:*:*:*:*:*:*
cpe:2.3:a:sangoma:certified_asterisk:20.7:cert2:*:*:*:*:*:*
Vendors & Products Sangoma
Sangoma asterisk
Sangoma certified Asterisk
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
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.
Title A malformed Contact or Record-Route URI in an incoming SIP request can cause Asterisk to crash when res_resolver_unbound is used
Weaknesses CWE-252
CWE-476
References
Metrics cvssV3_1

{'score': 5.7, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Nov 3, 2025, 10:04 PM
Reserved
Aug 2, 2024, 2:13 PM
Status
Modified
Published
Sep 5, 2024, 6:15 PM
Modified
Jun 17, 2026, 7:49 AM