The Service Assurance Agent (SAA) in Cisco IOS 12.0 through 12.2, aka Response Time Reporter (RTR), allows remote attackers to cause a denial of service (crash) via malformed RTR packets to port 1967.

IP Security VPN Services Module (VPNSM) in Cisco Catalyst 6500 Series Switch and the Cisco 7600 Series Internet Routers running IOS before 12.2(17b)SXA, before 12.2(17d)SXB, or before 12.2(14)SY03 could allow remote attackers to cause a denial of service (device crash and reload) via a malformed Internet Key Exchange (IKE) packet.

Buffer overflow in the Cisco Firewall Services Module (FWSM) in Cisco Catalyst 6500 and 7600 series devices allows remote attackers to cause a denial of service (crash and reload) via HTTP auth requests for (1) TACACS+ or (2) RADIUS authentication.

Cisco PIX firewall 6.2.x through 6.2.3, when configured as a VPN Client, allows remote attackers to cause a denial of service (dropped IPSec tunnel connection) via an IKE Phase I negotiation request to the outside interface of the firewall.

Cisco Firewall Services Module (FWSM) in Cisco Catalyst 6500 and 7600 series devices allows remote attackers to cause a denial of service (crash and reload) via an SNMPv3 message when snmp-server is set.

Cisco VPN 3000 series concentrators and Cisco VPN 3002 Hardware Client 2.x.x through 3.6.7A allow remote attackers to cause a denial of service (slowdown and possibly reload) via a flood of malformed ICMP packets.

The web server for Cisco Aironet AP1x00 Series Wireless devices running certain versions of IOS 12.2 allow remote attackers to cause a denial of service (reload) via a malformed URL.

A vulnerability in the web application for Cisco IP Phones could allow an unauthenticated, remote attacker to execute code with root privileges or cause a reload of an affected IP phone, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software fails to check the bounds of input data. An attacker could exploit this vulnerability by sending a crafted HTTP request to the web server of a targeted device. A successful exploit could allow the attacker to remotely execute code with root privileges or cause a reload of an affected IP phone, resulting in a DoS condition.

The lock manager in Cisco CNS Network Registrar 6.0 through 6.1.1.3 allows remote attackers to cause a denial of service (process crash) via a certain "unexpected packet sequence."

Cisco ONS15454 and ONS15327 running ONS before 3.4 allows attackers to cause a denial of service (reset) via an HTTP request to the TCC, TCC+ or XTC, in which the request contains an invalid CORBA Interoperable Object Reference (IOR).

Cisco CatOS 5.x before 5.5(20) through 8.x before 8.2(2) and 8.3(2)GLX, as used in Catalyst switches, allows remote attackers to cause a denial of service (system crash and reload) by sending invalid packets instead of the final ACK portion of the three-way handshake to the (1) Telnet, (2) HTTP, or (3) SSH services, aka "TCP-ACK DoS attack."

Cisco ONS15454 and ONS15327 running ONS before 3.4 allows attackers to cause a denial of service (reset to TCC, TCC+, TCCi or XTC) via a malformed HTTP request that does not contain a leading / (slash) character.

A vulnerability in the HTTP 2.0 request handling code of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause the Event Management Service daemon (emsd) to crash, resulting in a denial of service (DoS) condition. More Information: CSCvb14425. Known Affected Releases: 6.1.1.BASE. Known Fixed Releases: 6.1.2.6i.MGBL 6.1.22.9i.MGBL 6.2.1.14i.MGBL.

Buffer overflow in Cisco PIX Firewall 5.2.x to 5.2.8, 6.0.x to 6.0.3, 6.1.x to 6.1.3, and 6.2.x to 6.2.1 allows remote attackers to cause a denial of service via HTTP traffic authentication using (1) TACACS+ or (2) RADIUS.

A vulnerability in the Active Directory integration component of Cisco Identity Services Engine (ISE) could allow an unauthenticated, remote attacker to perform a denial of service (DoS) attack. More Information: CSCuw15041. Known Affected Releases: 1.2(1.199).

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.

The General Packet Radio Switching Tunneling Protocol 1 (aka GTPv1) implementation on Cisco ASR 5000 Packet Data Network Gateway devices before 19.4 allows remote attackers to cause a denial of service (Session Manager process restart) via a crafted GTPv1 packet, aka Bug ID CSCuz46198.

Cisco IOS 2.2(18)EW, 12.2(18)EWA, 12.2(14)SZ, 12.2(18)S, 12.2(18)SE, 12.2(18)SV, 12.2(18)SW, and other versions without the "no service dhcp" command, keep undeliverable DHCP packets in the queue instead of dropping them, which allows remote attackers to cause a denial of service (dropped traffic) via multiple undeliverable DHCP packets that exceed the input queue size.

Buffer overflows in Cisco Virtual Private Network (VPN) Client 3.5.4 and earlier allows remote attackers to cause a denial of service via (1) an Internet Key Exchange (IKE) with a large Security Parameter Index (SPI) payload, or (2) an IKE packet with a large number of valid payloads.

Cisco Virtual Private Network (VPN) Client software 2.x.x and 3.x before 3.0.5 allows remote attackers to cause a denial of service (crash) via TCP packets with source and destination ports of 137 (NETBIOS).

HTML interface for Cisco VPN 3000 Concentrator 2.x.x and 3.x.x before 3.0.3(B) allows remote attackers to cause a denial of service (CPU consumption) via a long URL request.

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 a long user name.

A vulnerability in the TCP Normalizer of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software operating in transparent mode could allow an unauthenticated, remote attacker to poison MAC address tables, resulting in a denial of service (DoS) vulnerability. This vulnerability is due to incorrect handling of certain TCP segments when the affected device is operating in transparent mode. An attacker could exploit this vulnerability by sending a crafted TCP segment through an affected device. A successful exploit could allow the attacker to poison the MAC address tables in adjacent devices, resulting in network disruption.

Memory leak in the Call Telephony Integration (CTI) Framework authentication for Cisco CallManager 3.0 and 3.1 before 3.1(3) allows remote attackers to cause a denial of service (crash and reload) via a series of authentication failures, e.g. via incorrect passwords.

Cisco Aironet before 11.21 with Telnet enabled allows remote attackers to cause a denial of service (reboot) via a series of login attempts with invalid usernames and passwords.

Web-based configuration utility in Cisco 600 series routers running CBOS 2.0.1 through 2.4.2ap binds itself to port 80 even when web-based configuration services are disabled, which could leave the router open to attack.

Cisco IOS 11.x and 12.0 with ATM support allows attackers to cause a denial of service via the undocumented Interim Local Management Interface (ILMI) SNMP community string.

Cisco CBOS 2.3.8 and earlier allows remote attackers to cause a denial of service via a series of large ICMP ECHO REPLY (ping) packets, which cause it to enter ROMMON mode and stop forwarding packets.

The log4jinit web application in Cisco Unified Communications Manager (UCM) does not properly validate authentication, which allows remote attackers to cause a denial of service (performance degradation) via unspecified use of this application, aka Bug ID CSCum05347.

Cisco Catalyst 5000 series switches 6.1(2) and earlier will forward an 802.1x frame on a Spanning Tree Protocol (STP) blocked port, which causes a network storm and a denial of service.

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.

Cisco devices IOS 12.0 and earlier allow a remote attacker to cause a crash, or bad route updates, via malformed BGP updates with unrecognized transitive attribute.

Cisco Internetwork Operating System (IOS) 12.0S through 12.3T attempts to process SNMP solicited operations on improper ports (UDP 162 and a randomly chosen UDP port), which allows remote attackers to cause a denial of service (device reload and memory corruption).

Cisco Catalyst 6000, 5000, or 4000 switches allow remote attackers to cause a denial of service by connecting to the SSH service with a non-SSH client, which generates a protocol mismatch error.

Cisco PIX Firewall 515 and 520 with 5.1.4 OS running aaa authentication to a TACACS+ server allows remote attackers to cause a denial of service via a large number of authentication requests.

The Web interface to Cisco 600 routers running CBOS 2.4.1 and earlier allow remote attackers to cause a denial of service via a URL that does not end in a space character.

Multiple Cisco networking products allow remote attackers to cause a denial of service on the local network via a series of ARP packets sent to the router's interface that contains a different MAC address for the router, which eventually causes the router to overwrite the MAC address in its ARP table.

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.

Cisco Gigabit Switch Routers (GSR) with Fast Ethernet / Gigabit Ethernet cards, from IOS versions 11.2(15)GS1A up to 11.2(19)GS0.2 and some versions of 12.0, do not properly handle line card failures, which allows remote attackers to bypass ACLs or force the interface to stop forwarding packets.

Cisco ONS 15327 before 4.1(3), ONS 15454 before 4.6(1), and ONS 15454 SD before 4.1(3) allows remote attackers to cause a denial of service (reset) by not sending the ACK portion of the TCP three-way handshake and sending an invalid response instead.

Cisco 11000 Series Content Services Switches (CSS) running WebNS 5.0(x) before 05.0(04.07)S, and 6.10(x) before 06.10(02.05)S allow remote attackers to cause a denial of service (device reset) via a malformed packet to UDP port 5002.

A vulnerability in the Cisco Unified Reporting upload tool accessed via the Cisco Unified Communications Manager could allow an unauthenticated, remote attacker to modify arbitrary files on the file system. More Information: CSCvb61698. Known Affected Releases: 11.5(1.11007.2). Known Fixed Releases: 12.0(0.98000.168) 12.0(0.98000.178) 12.0(0.98000.399) 12.0(0.98000.510) 12.0(0.98000.536) 12.0(0.98500.7).

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.

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.

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

OpenSSL 0.9.6 before 0.9.6d does not properly handle unknown message types, which allows remote attackers to cause a denial of service (infinite loop), as demonstrated using the Codenomicon TLS Test Tool.