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.

Unspecified vulnerability in Cisco IOS 12.2 and 12.4, when SSLVPN sessions, SSH sessions, or IKE encrypted nonces are enabled, allows remote attackers to cause a denial of service (device reload) via a crafted encrypted packet, aka Bug ID CSCsq24002.

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.

Unspecified vulnerability in Cisco IOS 12.0 through 12.4, when SIP voice services are enabled, allows remote attackers to cause a denial of service (device crash) via a valid SIP message.

Unspecified vulnerability in Cisco IOS 12.0 through 12.4, when configured with (1) IP Service Level Agreements (SLAs) Responder, (2) Session Initiation Protocol (SIP), (3) H.323 Annex E Call Signaling Transport, or (4) Media Gateway Control Protocol (MGCP) allows remote attackers to cause a denial of service (blocked input queue on the inbound interface) via a crafted UDP packet.