Vulnerable Systems:
* Cisco IOS Software configured for NAT support for SIP H.323 call signaling for H.323
* Cisco IOS Software configured for NAT support for SIP H.225.0 call signaling for H.323
The three vulnerabilities are triggered by transit traffic that needs to be processed by the NAT feature. Each vulnerability is independent of each other.
NAT for SIP DoS Vulnerability
SIP is a popular signaling protocol that is used to manage voice and video calls across IP networks such as the Internet. SIP is responsible for handling all aspects of call setup and termination. Voice and video are the most popular types of sessions that SIP handles, but the protocol has the flexibility to accommodate other applications that require call setup and termination.
NAT for SIP translates packets using UDP (port 5060) or TCP (port 5060) as the underlying transport protocol. The NAT for SIP DoS vulnerability can be exploited only with the use of UDP port 5060 packets.
NAT for H.323 DoS Vulnerability
H.323 is the International Telecommunication Union (ITU) standard for real-time multimedia communications and conferencing over packet-based (IP) networks. NAT for H.323 translates packets on TCP port 1720. There is a DoS vulnerability in the NAT procession of H.323 packets. The vulnerability does not require the completion of a TCP three-way handshake.
NAT for H.225.0 DoS vulnerability
H.323 is the ITU standard for real-time multimedia communications and conferencing over packet-based (IP) networks. A subset of the H.323 standard is H.225.0, a standard used for call signaling protocols and media stream packetization over IP networks. NAT for H.225.0 translates packets on TCP port 1720. There is a DoS vulnerability in the NAT translation of H.225.0 call signaling for H.323 packets.
