CVE-2024-42491: asterisk · Unchecked Return Value
Affects asteriskSource GCVE Database
Not known to be exploited · CVSS 5.7 Medium · fixed in 21.4.3 : update asterisk when convenient.
Data as of 30 Oct 2026, 02:22 UTC
Thin evidence
One scorer or none| CNA (GitHub_M) | CVSS 3.1 | 5.7 |
|---|
- Patch
- Available – fixed in 21.4.3, 20.9.3, 20.7-cert2 +2
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 5 Sep 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| asterisk asterisk | Affected
| Fixed in
|
AI-suggested
Users should upgrade to Asterisk versions 18.24.3, 20.9.3, 21.4.3, or certified versions 18.9-cert12 and 20.7-cert2 where the issue is fixed. Alternatively, as a workaround, disable the res_resolver_unbound module by adding 'noload = res_resolver_unbound.so' in modules.conf or set 'rewrite_contact = yes' on all PJSIP endpoints. Note that these workarounds may not be appropriate for all configurations, so upgrading is the recommended approach.
Description
CVE-2024-42491 is a vulnerability in Asterisk PBX prior to versions 18.24.3, 20.9.3, 21.4.3, and certain certified versions. When Asterisk sends a SIP request to a URI with a host starting with `.1` or `[.1]` while the res_resolver_unbound module is loaded, it crashes with a segmentation fault. The issue is fixed in the specified versions. Workarounds include disabling the res_resolver_unbound module or setting rewrite_contact to yes on all PJSIP endpoints, though these may not suit all configurations.
References
- github.com/asterisk/asterisk/security/advisories/GHSA-v428-g3cw-7hv9 (opens in a new tab)
- github.com/asterisk/asterisk/commit/42a2f4ccfa2c7062a15063e765916b3332e34cc4 (opens in a new tab)
- github.com/asterisk/asterisk/commit/4f01669c7c41c9184f3cce9a3cf1b2ebf6201742 (opens in a new tab)
- github.com/asterisk/asterisk/commit/50bf8d4d3064930d28ecf1ce3397b14574d514d2 (opens in a new tab)
- github.com/asterisk/asterisk/commit/7a0090325bfa9d778a39ae5f7d0a98109e4651c8 (opens in a new tab)
- github.com/asterisk/asterisk/commit/a15050650abf09c10a3c135fab148220cd41d3a0 (opens in a new tab)
- lists.debian.org/debian-lts-announce/2024/10/msg00016.html (opens in a new tab)