Medium severity · published Sep 5, 2024
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
5.7
CVSS
0.6%
EPSS
No
On KEV
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 vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
Required
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 48% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
AS
asterisk · asterisk
< 18.24.3; >= 19.0.0, < 20.9.3; >= 21.0.0, < 21.4.3; < 18.9-cert12; >= 19.0, < 20.7-cert2 · source: vendor, NVD
CA
Certified Asterisk · Sangoma
before 18.9; 18.9; 18.9; 18.9; 18.9; 18.9; +14 more · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2024-42491
CVE.org
https://www.cve.org/CVERecord?id=CVE-2024-42491
Patch
https://github.com/asterisk/asterisk/commit/42a2f4ccfa2c7062a15063e765916b3332e34cc4
Patch
https://github.com/asterisk/asterisk/commit/4f01669c7c41c9184f3cce9a3cf1b2ebf6201742
Patch
https://github.com/asterisk/asterisk/commit/50bf8d4d3064930d28ecf1ce3397b14574d514d2
Patch
https://github.com/asterisk/asterisk/commit/7a0090325bfa9d778a39ae5f7d0a98109e4651c8
Patch
https://github.com/asterisk/asterisk/commit/a15050650abf09c10a3c135fab148220cd41d3a0
Vendor Advisory
https://github.com/asterisk/asterisk/security/advisories/GHSA-v428-g3cw-7hv9
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