The TCP implementation in (1) Linux, (2) platforms based on BSD Unix, (3) Microsoft Windows, (4) Cisco products, and probably other operating systems allows remote attackers to cause a denial of service (connection queue exhaustion) via multiple vectors that manipulate information in the TCP state table, as demonstrated by sockstress.

A "logic error" in Cisco IOS 12.0 through 12.4, when a Multiprotocol Label Switching (MPLS) VPN with extended communities is configured, sometimes causes a corrupted route target (RT) to be used, which allows remote attackers to read traffic from other VPNs in opportunistic circumstances.

Unspecified vulnerability in Cisco IOS 12.0 through 12.4 allows remote attackers to cause a denial of service (device reload) via a crafted Protocol Independent Multicast (PIM) packet.

Stack-based buffer overflow in the Line Printer Daemon (LPD) in Cisco IOS before 12.2(18)SXF11, 12.4(16a), and 12.4(2)T6 allow remote attackers to execute arbitrary code by setting a long hostname on the target system, then causing an error message to be printed, as demonstrated by a telnet session to the LPD from a source port other than 515.

Cisco IOS 9.x, 10.x, 11.x, and 12.x and IOS XR 2.0.x, 3.0.x, and 3.2.x allows remote attackers to cause a denial of service or execute arbitrary code via a crafted IP option in the IP header in a (1) ICMP, (2) PIMv2, (3) PGM, or (4) URD packet.

Memory leak in the TCP listener in Cisco IOS 9.x, 10.x, 11.x, and 12.x allows remote attackers to cause a denial of service by sending crafted TCP traffic to an IPv4 address on the IOS device.

Cisco IOS allows remote attackers to cause a denial of service (crash) via a crafted IPv6 Type 0 Routing header.

Secure Shell (SSH) 2 in Cisco IOS 12.0 through 12.3 allows remote attackers to cause a denial of service (device reload) (1) via a username that contains a domain name when using a TACACS+ server to authenticate, (2) when a new SSH session is in the login phase and a currently logged in user issues a send command, or (3) when IOS is logging messages and an SSH session is terminated while the server is sending data.

Cisco IOS 12.0S through 12.3YH allows remote attackers to cause a denial of service (device restart) via a crafted IPv6 packet.

Cisco IOS 12.0 through 12.3YL, with BGP enabled and running the bgp log-neighbor-changes command, allows remote attackers to cause a denial of service (device reload) via a malformed BGP packet.