Cisco IOS 12.1(2)T, 12.1(3)T allow remote attackers to cause a denial of service (reload) via a connection to TCP ports 3100-3999, 5100-5999, 7100-7999 and 10100-10999.

Cisco 12000 with IOS 12.0 and line cards based on Engine 2 and earlier allows remote attackers to cause a denial of service (CPU consumption) by flooding the router with traffic that generates a large number of ICMP Unreachable replies.

PPTP implementation in Cisco IOS 12.1 and 12.2 allows remote attackers to cause a denial of service (crash) via a malformed packet.

Cisco 12000 with IOS 12.0 and line cards based on Engine 2 does not handle the "fragment" keyword in a compiled ACL (Turbo ACL) for packets that are sent to the router, which allows remote attackers to cause a denial of service via a flood of fragments.

Cisco VPN 3000 series concentrators before 2.5.2(F) allow remote attackers to cause a denial of service via an IP packet with an invalid IP option.

The HTTP server in Cisco IOS 12.0 through 12.1 allows local users to cause a denial of service (crash and reload) via a URL containing a "?/" string.

Cisco 600 routers running CBOS 2.4.1 and earlier allow remote attackers to cause a denial of service via a large ICMP echo (ping) packet.

Unspecified vulnerability in Cisco ASA 5500 Series Adaptive Security Appliance 7.0 before 7.0(8.10), 7.2 before 7.2(4.45), 8.0 before 8.0(5.1), 8.1 before 8.1(2.37), and 8.2 before 8.2(1.15); and Cisco PIX 500 Series Security Appliance; allows remote attackers to cause a denial of service (active IPsec tunnel loss and prevention of new tunnels) via a malformed IKE message through an existing tunnel to UDP port 4500, aka Bug ID CSCtc47782.

CBOS 2.4.1 and earlier in Cisco 600 routers allows remote attackers to cause a denial of service via a slow stream of TCP SYN packets.

Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allow remote attackers to cause a denial of service (ASDM syslog outage) via a long URL, aka Bug IDs CSCsm11264 and CSCtb92911.

Buffer overflow in Cisco TACACS+ tac_plus server allows remote attackers to cause a denial of service via a malformed packet with a long length field.

Memory leak in the gk_circuit_info_do_in_acf function in the H.323 implementation in Cisco IOS before 15.0(1)XA allows remote attackers to cause a denial of service (memory consumption) via a large number of calls over a long duration, as demonstrated by InterZone Clear Token (IZCT) test traffic, aka Bug ID CSCsz72535.

Cisco IOS 11.x and 12.x allows remote attackers to cause a denial of service by sending the ENVIRON option to the Telnet daemon before it is ready to accept it, which causes the system to reboot.

Denial of service in Cisco routers running NAT via a PORT command from an FTP client to a Telnet port.

Vulnerability in Cisco 7xx series routers allows a remote attacker to cause a system reload via a TCP connection to the router's TELNET port.

Cisco Catalyst LAN switches running Catalyst 5000 supervisor software allows remote attackers to perform a denial of service by forcing the supervisor module to reload.

Denial of service in Cisco IOS web server allows attackers to reboot the router using a long URL.

Buffer overflow in Cisco 7xx routers through the telnet service.

Attackers can crash a Cisco IOS router or device, provided they can get to an interactive prompt (such as a login). This applies to some IOS 9.x, 10.x, and 11.x releases.

Cisco IOS 12.0 and other versions can be crashed by malicious UDP packets to the syslog port.

The DHCPv6 server in Cisco IOS on ASR 9000 devices with software 5.2.0 Base allows remote attackers to cause a denial of service (process reset) via crafted packets, aka Bug ID CSCun36525.

The Cisco IronPort Email Security Appliance (ESA) allows remote attackers to cause a denial of service (CPU consumption) via long Subject headers in e-mail messages, aka Bug ID CSCzv93864.

Cisco IOS XR allows remote attackers to cause a denial of service (LISP process reload) by establishing many LISP TCP sessions, aka Bug ID CSCuq90378.

The Data-link Switching (DLSw) feature in Cisco IOS 11.0 through 12.4 allows remote attackers to cause a denial of service (device reload) via "an invalid value in a DLSw message... during the capabilities exchange."

Cisco IP Phones 7902/7905/7912, ATA 186/188, Unity Express, ACNS, and Subscriber Edge Services Manager (SESM) allows remote attackers to cause a denial of service (crash or instability) via a compressed DNS packet with a label length byte with an incorrect offset.

The DHCPv6 implementation in Cisco IOS XR allows remote attackers to cause a denial of service (process hang) via a malformed packet, aka Bug ID CSCul80924.

Cisco IOS XR 5.1 and earlier allows remote attackers to cause a denial of service (process reload) via a malformed RSVP packet, aka Bug ID CSCuq12031.

Cisco Wide Area Application Services (WAAS) 5.3(.5a) and earlier, when SharePoint acceleration is enabled, does not properly parse SharePoint responses, which allows remote attackers to cause a denial of service (application-optimization handler reload) via a crafted SharePoint application, aka Bug ID CSCue47674.

The DHCPv6 implementation in Cisco IOS XR allows remote attackers to cause a denial of service (device crash) via a malformed packet, aka Bug IDs CSCum85558, CSCum20949, CSCul61849, and CSCul71149.

Cisco IOS 15.4(3)S0b on ASR901 devices makes incorrect decisions to use the CPU for IPv4 packet processing, which allows remote attackers to cause a denial of service (BGP neighbor flapping) by sending many crafted IPv4 packets, aka Bug ID CSCuo29736.

Cisco 2611 router running IOS 12.1(6.5), possibly an interim release, allows remote attackers to cause a denial of service via port scans such as (1) scanning all ports on a single host and (2) scanning a network of hosts for a single open port through the router. NOTE: the vendor could not reproduce this issue, saying that the original reporter was using an interim release of the software.

Cisco IOS 15.2(4)M4 on Cisco Unified Border Element (CUBE) devices allows remote attackers to cause a denial of service (input-queue consumption and traffic-processing outage) via crafted RTCP packets, aka Bug ID CSCuj72215.

The DHCPv6 server module in Cisco CNS Network Registrar 7.1 allows remote attackers to cause a denial of service (daemon reload) via a malformed DHCPv6 packet, aka Bug ID CSCuo07437.

Memory leak in the SIP inspection engine in Cisco Adaptive Security Appliance (ASA) Software allows remote attackers to cause a denial of service (memory consumption and instability) via crafted SIP packets, aka Bug ID CSCuf67469.

Memory leak in the GUI in the Impact server in Cisco Hosted Collaboration Solution (HCS) allows remote attackers to cause a denial of service (memory consumption) via unspecified vectors, aka Bug ID CSCub58999.

Cisco ONS 15454 controller cards with software 10.0 and earlier allow remote attackers to cause a denial of service (card reload) via a crafted HTTP URI, aka Bug ID CSCun06870.

Cisco CallManager (CCM) 3.2 and earlier, 3.3 before 3.3(5), 4.0 before 4.0(2a)SR2b, and 4.1 4.1 before 4.1(3)SR1 allows remote attackers to cause a denial of service (memory consumption and restart) via crafted packets to (1) the CTI Manager (ctimgr.exe) or (2) the CallManager (ccm.exe).

Cisco ONS 15454 controller cards with software 9.6 and earlier allow remote attackers to cause a denial of service (flash write outage) via a TCP FIN attack that triggers file-descriptor exhaustion, aka Bug ID CSCug97315.

The Java-based software in Cisco Hosted Collaboration Solution (HCS) allows remote attackers to cause a denial of service (closing of TCP ports) via unspecified vectors, aka Bug IDs CSCug77633, CSCug77667, CSCug78266, CSCug82795, and CSCuh58643.

The SNMP module in Cisco IOS XR allows remote attackers to cause a denial of service (process reload) via a request for an unspecified MIB, aka Bug ID CSCuh43144.

The tNetTaskLimit process on the Transport Node Controller (TNC) on Cisco ONS 15454 devices with software 9.6 and earlier does not properly prioritize health pings, which allows remote attackers to cause a denial of service (watchdog timeout and TNC reset) via a flood of network traffic, aka Bug ID CSCud97155.

The PPTP-ALG component in CRS Carrier Grade Services Engine (CGSE) and ASR 9000 Integrated Service Module (ISM) in Cisco IOS XR allows remote attackers to cause a denial of service (module reset) via crafted packet streams, aka Bug ID CSCue91963.

Buffer overflow in the web-application interface on Cisco 9900 IP phones allows remote attackers to cause a denial of service (webapp interface outage) via long values in unspecified fields, aka Bug ID CSCuh10343.

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

The Java process in the Impact server in Cisco Prime Central for Hosted Collaboration Solution (HCS) allows remote attackers to cause a denial of service (process crash) via a flood of TCP packets, aka Bug ID CSCug57345.

Cisco Secure Access Control System (ACS) does not properly implement an incoming-packet firewall rule, which allows remote attackers to cause a denial of service (process crash) via a flood of crafted packets, aka Bug ID CSCui51521.

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 NX-OS 5.0 and earlier on MDS 9000 devices allows remote attackers to cause a denial of service (supervisor CPU consumption) via Authentication Header (AH) authentication in a Virtual Router Redundancy Protocol (VRRP) frame, aka Bug ID CSCte27874.

Cisco Secure Access Control System (ACS) does not properly handle requests to read from the TACACS+ socket, which allows remote attackers to cause a denial of service (process crash) via malformed TCP packets, aka Bug ID CSCuh12488.

Cisco VPN 3000 Concentrator 2.2.x, 3.6(Rel), and 3.x before 3.5.5, allows remote attackers to cause a denial of service via (1) malformed or (2) large ISAKMP packets.