Cross-site scripting (XSS) vulnerability in the SIP implementation on the Cisco SPA8000 and SPA8800 before 6.1.11, SPA2102 and SPA3102 before 5.2.13, and SPA 500 series IP phones before 7.4.9 allows remote attackers to inject arbitrary web script or HTML via the FROM field of an INVITE message, aka Bug IDs CSCtr27277, CSCtr27256, CSCtr27274, and CSCtr14715.

Multiple TCP implementations with Protection Against Wrapped Sequence Numbers (PAWS) with the timestamps option enabled allow remote attackers to cause a denial of service (connection loss) via a spoofed packet with a large timer value, which causes the host to discard later packets because they appear to be too old.

Cisco IOS 11.x and 12.x allows remote attackers to cause a denial of service by sending the ENVIRON option to the Telnet daemon before it is ready to accept it, which causes the system to reboot.