Cisco IOS 12.2 through 12.4, when certain PMTUD, SNAT, or window-size configurations are used, allows remote attackers to cause a denial of service (infinite loop, and device reload or hang) via a TCP segment with crafted options, aka Bug ID CSCsz75186.

Unspecified vulnerability in the SIP implementation in Cisco IOS 12.3 and 12.4 allows remote attackers to execute arbitrary code via a malformed SIP message, aka Bug ID CSCsz89904, the "SIP Packet Parsing Arbitrary Code Execution Vulnerability."

Cisco IOS 12.1 through 12.4, when Cisco Unified Communications Manager Express (CME) or Cisco Unified Survivable Remote Site Telephony (SRST) is enabled, allows remote attackers to cause a denial of service (device reload) via a malformed Skinny Client Control Protocol (SCCP) message, aka Bug ID CSCsz48614, the "SCCP Packet Processing Denial of Service Vulnerability."

Unspecified vulnerability in the SIP implementation in Cisco IOS 12.3 and 12.4 allows remote attackers to execute arbitrary code via a malformed SIP message, aka Bug ID CSCsz48680, the "SIP Message Processing Arbitrary Code Execution Vulnerability."

Cisco IOS 12.1 through 12.4, when Cisco Unified Communications Manager Express (CME) or Cisco Unified Survivable Remote Site Telephony (SRST) is enabled, allows remote attackers to cause a denial of service (device reload) via a malformed Skinny Client Control Protocol (SCCP) message, aka Bug ID CSCsz49741, the "SCCP Request Handling Denial of Service Vulnerability."

Unspecified vulnerability in Cisco IOS 12.2 through 12.4 allows remote attackers to cause a denial of service (device reload) via a crafted H.323 packet, aka Bug ID CSCsz38104.

Cisco IOS 12.0 through 12.4, when IP-based tunnels and the Cisco Express Forwarding feature are enabled, allows remote attackers to cause a denial of service (device reload) via a malformed packet that is not properly handled during switching from one tunnel to a second tunnel, aka Bug IDs CSCsh97579 and CSCsq31776.

Cisco IOS 12.0 through 12.4, when IP-based tunnels and the Cisco Express Forwarding feature are enabled, allows remote attackers to cause a denial of service (device reload) via malformed packets, aka Bug ID CSCsx70889.

The SSLVPN feature in Cisco IOS 12.3 through 12.4 allows remote attackers to cause a denial of service (device reload or hang) via a crafted HTTPS packet.

The (1) Cisco Unified Communications Manager Express; (2) SIP Gateway Signaling Support Over Transport Layer Security (TLS) Transport; (3) Secure Signaling and Media Encryption; (4) Blocks Extensible Exchange Protocol (BEEP); (5) Network Admission Control HTTP Authentication Proxy; (6) Per-user URL Redirect for EAPoUDP, Dot1x, and MAC Authentication Bypass; (7) Distributed Director with HTTP Redirects; and (8) TCP DNS features in Cisco IOS 12.0 through 12.4 do not properly handle IP sockets, which allows remote attackers to cause a denial of service (outage or resource consumption) via a series of crafted TCP packets.