What happened
A vulnerability has been found in Kamailio 5.5. This affects the function yyerror_at of the file src/core/cfg.y of the component Grammar Rule Handler. Such manipulation leads to null pointer dereference. The attack needs to be performed locally. The exploit has been disclosed to the public and may be used. The actual existence of this vulnerability is currently in question. This attack requires manipulating config files which might not be a realistic scenario in many cases. The vendor was contacted early about this disclosure but did not respond in any way.
Affected versions
Kamailio: 5.5 Fixed: See vendor advisory.
Why it matters
Review the vendor advisory and exposure of the affected product to determine operational impact.
Detection & mitigation
- Apply vendor-provided updates or mitigations.
- Review affected product exposure and access logs.