Cisco IOS before 15.1(1)SY, when Multicast Listener Discovery (MLD) snooping is enabled, allows remote attackers to cause a denial of service (CPU consumption or device crash) via MLD packets on a network that contains many IPv6 hosts, aka Bug ID CSCtr88193.
Cisco IOS before 15.3(1)T on Cisco 2900 devices, when a VWIC2-2MFT-T1/E1 card is configured for TDM/HDLC mode, allows remote attackers to cause a denial of service (serial-interface outage) via certain Frame Relay traffic, aka Bug ID CSCub13317.
Cisco IOS before 15.1(1)SY allows local users to cause a denial of service (device reload) by establishing an outbound SSH session, aka Bug ID CSCto00318.
Cisco IOS before 15.3(2)T, when scansafe is enabled, allows remote attackers to cause a denial of service (latency) via SYN packets that are not accompanied by SYN-ACK packets from the Scan Safe Tower, aka Bug ID CSCub85451.
The ios-authproxy implementation in Cisco IOS before 15.1(1)SY3 allows remote attackers to cause a denial of service (webauth and HTTP service outage) via vectors that trigger incorrectly terminated HTTP sessions, aka Bug ID CSCtz99447.
Cisco IOS before 15.1(2)SY allows remote authenticated users to cause a denial of service (device crash) by establishing an SSH session from a client and then placing this client into a (1) slow or (2) idle state, aka Bug ID CSCto87436.
Cisco IOS before 15.1(1)SY1 allows remote authenticated users to cause a denial of service (device reload) by establishing a VPN session and then sending malformed IKEv2 packets, aka Bug ID CSCub39268.
The Flex-VPN load-balancing feature in the ipsec-ikev2 implementation in Cisco IOS before 15.1(1)SY3 does not require authentication, which allows remote attackers to trigger the forwarding of VPN traffic to an attacker-controlled destination, or the discarding of this traffic, by arranging for an arbitrary device to become a cluster member, aka Bug ID CSCub93641.
Cisco IOS before 12.2(50)SY1 allows remote authenticated users to cause a denial of service (memory consumption) via a sequence of VTY management sessions (aka exec sessions), aka Bug ID CSCtn43662.
The ACL implementation in Cisco IOS before 15.1(1)SY on Catalyst 6500 and 7600 devices allows local users to cause a denial of service (device reload) via a "no object-group" command followed by an object-group command, aka Bug ID CSCts16133.