Cisco IOS 12.0 to 12.4 might allow remote attackers to execute arbitrary code via a heap-based buffer overflow in system timers. NOTE: this issue does not correspond to a specific vulnerability, rather a general weakness that only increases the feasibility of exploitation of any vulnerabilities that might exist. Such design-level weaknesses normally are not included in CVE, so perhaps this issue should be REJECTed.
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.
Cisco IOS 12.1T, 12.2, 12.2T, 12.3 and 12.3T, with Multi Protocol Label Switching (MPLS) installed but disabled, allows remote attackers to cause a denial of service (device reload) via a crafted packet sent to the disabled interface.
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.
Memory leak in Secure Shell (SSH) in Cisco IOS 12.0 through 12.3, when authenticating against a TACACS+ server, allows remote attackers to cause a denial of service (memory consumption) via an incorrect username or password.
Cisco IOS 12.2(15) and earlier allows remote attackers to cause a denial of service (refused VTY (virtual terminal) connections), via a crafted TCP connection to the Telnet or reverse Telnet port.
Cisco VACM (View-based Access Control MIB) for Catalyst Operating Software (CatOS) 5.5 and 6.1 and IOS 12.0 and 12.1 allows remote attackers to read and modify device configuration via the read-write community string.
Cisco IOS 11.1(x) through 11.3(x) and 12.0(x) through 12.2(x), when configured for BGP routing, allows remote attackers to cause a denial of service (device reload) via malformed BGP (1) OPEN or (2) UPDATE messages.
Multiple vulnerabilities in the H.323 protocol implementation for Cisco IOS 11.3T through 12.2T allow remote attackers to cause a denial of service and possibly execute arbitrary code, as demonstrated by the NISCC/OUSPG PROTOS test suite for the H.225 protocol.
Cisco IOS 12.0 through 12.2, when IP routing is disabled, accepts false ICMP redirect messages, which allows remote attackers to cause a denial of service (network routing modification).