Henning Westerholt

**Name of the Vulnerable Software and Affected Versions** Kamailio versions prior to 5.0.7 Kamailio versions 5.1.x prior to 5.1.4 **Description** A crafted SIP message with an invalid Via header can cause a segmentation fault and crash Kamailio due to missing input validation in the `crcitt string array` core function for calculating a CRC hash for To tags. An additional error is present in the `check via address` core function, which also misses input validation. This could result in denial of service and potentially the execution of arbitrary code. **Recommendations** For Kamailio versions prior to 5.0.7, update to version 5.0.7 or later. For Kamailio versions 5.1.x prior to 5.1.4, update to version 5.1.4 or later.

**Name of the Vulnerable Software and Affected Versions** Kamailio versions prior to 5.0.7 Kamailio versions 5.1.x prior to 5.1.4 **Description** A crafted SIP message with a double "To" header and an empty "To" tag can cause a segmentation fault and crash due to missing input validation in the `build res buf from sip req` core function. This could result in denial of service and potentially the execution of arbitrary code. **Recommendations** For Kamailio versions prior to 5.0.7, update to version 5.0.7 or later. For Kamailio versions 5.1.x prior to 5.1.4, update to version 5.1.4 or later. As a temporary workaround, consider implementing additional input validation for SIP messages to prevent crashes.