Mu Dynamics discovered and helped remediate a new programming flaw in ReSIProcate: A remotely exploitable Denial of Service vulnerability. The ReSIProcate components, particularly the SIP stack, is currently used in several Voice over IP (VoIP) commercial and open-source products. The project exists to maintain a complete, correct, and commercially usable implementation of SIP and a few related protocols.
Affected products/versions: repro SIP proxy/registrar 1.3.2; however any product using the ReSIProcate SIP stack 1.3.2 may also be vulnerable.
Product overview: ReSIProcate is a SIP stack. SIP is a protocol used for session establishment that is widely used to support voice-over-IP telephony. “repro” is a SIP proxy/registrar that uses the ReSIProcate SIP stack.
Vulnerability details: A malformed INVITE or OPTIONS message to the “repro” SIP proxy/ registrar can crash the process. The crash is caused by an assertion failure that occurs when the domain name in the request line URI is too long.
Vendor solution: Update to 1.3.3. This bug was also fixed by the ReSIProcate development team in SVN on April 23, 2008 (revision 7628).