A vulnerability in the TCP syslog module of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to exhaust the 1550-byte buffers on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to a missing boundary check in an internal function. An attacker could exploit this vulnerability by establishing a man-in-the-middle position between an affected device and its configured TCP syslog server and then maliciously modifying the TCP header in segments that are sent from the syslog server to the affected device. A successful exploit could allow the attacker to exhaust buffer on the affected device and cause all TCP-based features to stop functioning, resulting in a DoS condition. The affected TCP-based features include AnyConnect SSL VPN, clientless SSL VPN, and management connections such as Secure Shell (SSH), Telnet, and HTTPS.

Cisco IOS 12.1, 12.2, 12.3, and 12.4, with IPv4 UDP services and the IPv6 protocol enabled, allows remote attackers to cause a denial of service (device crash and possible blocked interface) via a crafted IPv6 packet to the device.

A vulnerability in the email message scanning feature of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause a temporary denial of service (DoS) condition on an affected device. The vulnerability is due to inadequate parsing mechanisms for specific email body components. An attacker could exploit this vulnerability by sending a malicious email containing a high number of shortened URLs through an affected device. A successful exploit could allow the attacker to consume processing resources, causing a DoS condition on an affected device. To successfully exploit this vulnerability, certain conditions beyond the control of the attacker must occur.

Cisco IOS 12.0 through 12.4 allows remote attackers to cause a denial of service (device crash) via (1) "abnormal" MGCP messages, aka CSCsd81407; and (2) a large facsimile packet, aka CSCej20505.

Cisco IOS on Aironet access points, when "dot11 aaa authenticator" debugging is enabled, allows remote attackers to cause a denial of service via a malformed EAP packet, aka Bug ID CSCul15509.

The SIP IX implementation in Cisco TelePresence Video Communication Server (VCS) and Expressway Software before X8.1.1 allows remote attackers to cause a denial of service (device reload) via crafted SDP packets, aka Bug ID CSCuo42252.

Cisco IOS 12.2 and 15.0 through 15.3, when used with the Kailash FPGA before 2.6 on RSP720-3C-10GE and RSP720-3CXL-10GE devices, allows remote attackers to cause a denial of service (route switch processor outage) via crafted IP packets, aka Bug ID CSCug84789.

Cisco TelePresence ISDN Gateway with software before 2.2(1.92) allows remote attackers to cause a denial of service (D-channel call outage) via a crafted Q.931 STATUS message, aka Bug ID CSCui50360.

Race condition in the cut-through proxy feature in Cisco Firewall Services Module (FWSM) Software 3.x before 3.2(28) and 4.x before 4.1(15) allows remote attackers to cause a denial of service (device reload) via certain matching traffic, aka Bug ID CSCuj16824.

The IPsec implementation in Cisco Adaptive Security Appliance (ASA) Software 9.1 before 9.1(1.7), when an IPsec VPN tunnel is enabled, allows remote attackers to cause a denial of service (device reload) via a (1) ICMP or (2) ICMPv6 packet that is improperly handled during decryption, aka Bug ID CSCue18975.

The TLS/SSLv3 module on Cisco ONS 15454 controller cards allows remote attackers to cause a denial of service (card reset) via crafted (1) TLS or (2) SSLv3 packets, aka Bug ID CSCuh34787.

Cisco 9900 fourth-generation IP phones do not properly perform SDP negotiation, which allows remote attackers to cause a denial of service (device reboot) via crafted SDP packets, aka Bug ID CSCuf06698.

Cisco Adaptive Security Appliances (ASA) devices, when SMP is used, do not properly process X.509 certificates, which allows remote attackers to cause a denial of service (device crash) via a large volume of (1) SSL or (2) TLS traffic, aka Bug ID CSCuh19462.

The DSP card on Cisco TelePresence MCU 4500 and 4501 devices before 4.3(2.30), TelePresence MCU MSE 8510 devices before 4.3(2.30), and TelePresence Server before 2.3(1.55) does not properly validate H.264 data, which allows remote attackers to cause a denial of service (device reload) via crafted RTP packets in a (1) SIP session or (2) H.323 session, aka Bug IDs CSCuc11328 and CSCub05448.

Cisco Prime Central for Hosted Collaboration Solution (HCS) Assurance 8.6 and 9.0 allows remote attackers to cause a denial of service (CPU consumption and monitoring outage) via malformed TLS messages to TCP port (1) 9043 or (2) 9443, aka Bug ID CSCuc07155.

The Intrusion Prevention System (IPS) feature in Cisco IOS 12.3 through 12.4 and 15.0 through 15.2, in certain configurations of enabled categories and missing signatures, allows remote attackers to cause a denial of service (device reload) via DNS packets, aka Bug ID CSCtw55976.

The AAA functionality in the IPv4 SSL VPN implementations on Cisco Adaptive Security Appliances (ASA) 5500 series devices, and the ASA Services Module (ASASM) in Cisco Catalyst 6500 series devices, with software 8.2 before 8.2(5.30) and 8.3 before 8.3(2.34) allows remote attackers to cause a denial of service (device reload) via a crafted authentication response, aka Bug ID CSCtz04566.

The DCERPC inspection engine on Cisco Adaptive Security Appliances (ASA) 5500 series devices, and the ASA Services Module (ASASM) in Cisco Catalyst 6500 series devices, with software 8.3 before 8.3(2.25), 8.4 before 8.4(2.5), and 8.5 before 8.5(1.13) and the Firewall Services Module (FWSM) 4.1 before 4.1(7) in Cisco Catalyst 6500 series switches and 7600 series routers allows remote attackers to cause a denial of service (device reload) via a crafted DCERPC packet, aka Bug IDs CSCtr21376 and CSCtr27524.

Race condition in the HTTP Deep Packet Inspection (DPI) feature in Cisco Adaptive Security Appliance (ASA) Software 8.2.x before 8.2(5.46), 8.3.x before 8.3(2.39), 8.4.x before 8.4(5.5), 8.5.x before 8.5(1.18), 8.6.x before 8.6(1.12), 8.7.x before 8.7(1.4), 9.0.x before 9.0(1.4), and 9.1.x before 9.1(1.2), in certain conditions involving the spoof-server option or ActiveX or Java response inspection, allows remote attackers to cause a denial of service (device reload) via a crafted HTTP response, aka Bug ID CSCud37992.

Cisco IOS XR 3.8.1 through 4.2.0 does not properly process fragmented packets within the RP-A, RP-B, PRP, and DRP-B route-processor components, which allows remote attackers to cause a denial of service (transmission outage) via (1) IPv4 or (2) IPv6 traffic, aka Bug ID CSCuh30380.

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a denial of service (DoS) condition. This vulnerability is due to improper input validation when parsing HTTPS requests. An attacker could exploit this vulnerability by sending a malicious HTTPS request to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

A vulnerability in the DNS application layer gateway (ALG) functionality used by Network Address Translation (NAT) in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to a logic error that occurs when an affected device inspects certain DNS packets. An attacker could exploit this vulnerability by sending crafted DNS packets through an affected device that is performing NAT for DNS packets. A successful exploit could allow an attacker to cause the device to reload, resulting in a denial of service (DoS) condition on an affected device. The vulnerability can be exploited only by traffic that is sent through an affected device via IPv4 packets. The vulnerability cannot be exploited via IPv6 traffic.

A vulnerability in the Border Gateway Protocol (BGP) Multicast VPN (MVPN) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an affected device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of a specific type of BGP MVPN update message. An attacker could exploit this vulnerability by sending this specific, valid BGP MVPN update message to a targeted device. A successful exploit could allow the attacker to cause one of the BGP-related routing applications to restart multiple times, leading to a system-level restart. Note: The Cisco implementation of BGP accepts incoming BGP traffic from only explicitly configured peers. To exploit this vulnerability, an attacker must send a specific BGP MVPN update message over an established TCP connection that appears to come from a trusted BGP peer. To do so, the attacker must obtain information about the BGP peers in the trusted network of the affected system.