The Thomson ST 2030 SIP phone with software 1.52.1 allows remote attackers to cause a denial of service (device hang) via an INVITE message with a Via header that contains a '/' (slash) instead of the required space following the SIP version number.

The Thomson ST 2030 SIP phone with software 1.52.1 allows remote attackers to cause a denial of service (device hang) via (1) an empty SIP message or (2) a SIP INVITE message with a malformed To header, different vectors than CVE-2007-4553.