Oulu University has discovered a variety of vulnerabilities affecting products that implement the Session Initiation Protocol (SIP). These vulnerabiltites affect a wide variety of products, with impacts ranging from denial of service to execution of arbitrary code. SIP is used in Voice Over Internet (VoIP), instant messaging, telephony, and various other applications and devices.
The Oulu University Secure Programming Group (OUSPG) has discovered a variety of vulnerabilities in multiple implementations of the Session Initiation Protocol (SIP). OUSPG has previously conducted research into vulnerabilities in various protocol implementations, including LDAP, culminating in CERT Advisory CA-2001-18 and SNMP, resulting in CERT Advisory CA-2002-03. OUSPG has again asked us to coordinate with them in letting affected vendors know of their findings.
The Session Initiation Protocol (SIP) is a signaling protocol for various instant messaging, Voice Over Internet Protocol (VoIP), and other telephony applications. OUSPG has focused on a subset of SIP as the subject protocol for vulnerability assessment. Information about SIP can be found on the IETF Charter page for SIP. OUSPG is has released the results of their investigations to the public. More details may be found in CERT Advisory CA-2003-06.
Impacts range from unexpected system behavior and denial of service to execution of arbitrary code.
Upgrade or apply the patches as specified by your vendor.
Vulnerable applications supporting the Session Initiation Protocol (SIP) may have access blocked at a network perimeter on ports 5060/tcp and 5060/udp.
The CERT Coordination Center thanks the Oulu University Secure Programming Group for reporting these vulnerabilities, for providing detailed technical analyses, and for assisting us in preparing this advisory. We would also like to acknowlede the "RedSkins" project of "MediaTeam Oulu" for their support of this research.