Cisco IOS contains an unspecified vulnerability that may block further telnet, reverse telnet, Remote Shell (RSH), Secure Shell (SSH), and in some cases, Hypertext Transport Protocol (HTTP) access to the Cisco device.
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Multiple versions of Cisco ONS 15327, ONS 15454, and ONS 15454 SDH, including 4.6(0) and 4.6(1), 4.5(x), 4.1(0) to 4.1(3), 4.0(0) to 4.0(2), and earlier versions, and ONS 15600 1.x(x), allows remote attackers to cause a denial of service (control card reset) via malformed (1) TCP and (2) UDP packets.
Cisco IOS 15.2S allows remote attackers to cause a denial of service (interface queue wedge) via malformed UDP traffic on port 465, aka Bug ID CSCts48300.
The CSAdmin web administration interface for Cisco Secure Access Control Server (ACS) 3.2(2) build 15 allows remote attackers to cause a denial of service (hang) via a flood of TCP connections to port 2002.
Cisco Carrier Routing System 3.9.1 allows remote attackers to cause a denial of service (Metro subsystem crash) via a fragmented GRE packet, aka Bug ID CSCts14887.
Multiple versions of Cisco ONS 15327, ONS 15454, and ONS 15454 SDH, including 4.6(0) and 4.6(1), 4.5(x), 4.1(0) to 4.1(3), 4.0(0) to 4.0(2), and earlier versions, allows remote attackers to cause a denial of service (control card reset) via a large number of TCP connections with an invalid response instead of the final ACK (TCP-ACK).
Cisco voice products, when running the IBM Director Agent on IBM servers before OS 2000.2.6, allows remote attackers to cause a denial of service (CPU consumption) via arbitrary packets to TCP port 14247, as demonstrated using port scanning.
Multiple versions of Cisco ONS 15327, ONS 15454, and ONS 15454 SDH, including 4.1(0) to 4.1(2), 4.5(x), 4.0(0) to 4.0(2), and earlier versions, allows remote attackers to cause a denial of service (control card reset) via malformed SNMP packets.
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.
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 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 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.
Cisco Unified Contact Center Express (aka CCX) 8.0 and 8.5 allows remote attackers to cause a denial of service via network traffic, as demonstrated by an SEC-BE-STABLE test case, aka Bug ID CSCth33834.
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 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 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.
The web administration interface (mainApp) to Cisco IDS before 4.1(5c), and IPS 5.0 before 5.0(6p1) and 5.1 before 5.1(2) allows remote attackers to cause a denial of service (unresponsive device) via a crafted SSLv2 Client Hello packet.
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.
The SSL/TLS handshaking code in OpenSSL 0.9.7a, 0.9.7b, and 0.9.7c, when using Kerberos ciphersuites, does not properly check the length of Kerberos tickets during a handshake, which allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that causes an out-of-bounds read.
The DNS server for Cisco Content Service Switch (CSS) 11000 and 11500, when prompted for a nonexistent AAAA record, responds with response code 3 (NXDOMAIN or "Name Error") instead of response code 0 ("No Error"), which allows remote attackers to cause a denial of service (inaccessible domain) by forcing other DNS servers to send and cache a request for a AAAA record to the vulnerable server.
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.
OpenSSL 0.9.6k allows remote attackers to cause a denial of service (crash via large recursion) via malformed ASN.1 sequences.
The do_change_cipher_spec function in OpenSSL 0.9.6c to 0.9.6k, and 0.9.7a to 0.9.7c, allows remote attackers to cause a denial of service (crash) via a crafted SSL/TLS handshake that triggers a null dereference.
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.
Cisco VPN 3000 series concentrators and Cisco VPN 3002 Hardware Client 2.x.x through 3.6.7 allows remote attackers to cause a denial of service (reload) via a malformed SSH initialization packet.
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.
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.
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.
STCAPP (aka the SCCP telephony control application) on Cisco IOS before 15.0(1)XA1 does not properly handle multiple calls to a shared line, which allows remote attackers to cause a denial of service (port hang) by simultaneously ending two calls that were controlled by CallManager Express (CME), aka Bug ID CSCtd42552.
The design of the Hot Standby Routing Protocol (HSRP), as implemented on Cisco IOS 12.1, when using IRPAS, allows remote attackers to cause a denial of service (CPU consumption) via a router with the same IP address as the interface on which HSRP is running, which causes a loop.
Cisco SN 5420 Storage Router 1.1(5) and earlier allows remote attackers to cause a denial of service (halt) via a fragmented packet to the Gigabit interface.
Cisco VPN 3000 Concentrator 2.2.x, and 3.x before 3.5.3, allows remote attackers to cause a denial of service (crash) via a long (1) username or (2) password to the HTML login interface.
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.
emWEB on Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allows remote attackers to cause a denial of service (daemon crash) via a request for a document whose name contains space characters, aka Bug ID CSCsy08416.
The LAN-to-LAN IPSEC capability for Cisco VPN 3000 Concentrator 2.2.x, and 3.x before 3.5.4, allows remote attackers to cause a denial of service via an incoming LAN-to-LAN connection with an existing security association with another device on the remote network, which causes the concentrator to remove the previous connection.
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.
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.
Cisco IOS 11.1 through 12.2, when HSRP support is not enabled, allows remote attackers to cause a denial of service (CPU consumption) via randomly sized UDP packets to the Hot Standby Routing Protocol (HSRP) port 1985.
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 SN 5420 Storage Router 1.1(5) and earlier allows remote attackers to cause a denial of service (router crash) via an HTTP request with large headers.
The web management interface for Cisco Content Service Switch (CSS) 11000 switches allows remote attackers to cause a denial of service (soft reset) via (1) an HTTPS POST request, or (2) malformed XML data.
Cisco Unified Personal Communicator 7.0 (1.13056) does not free allocated memory for received data and does not perform validation if memory allocation is successful, causing a remote denial of service condition.
Cisco IOS XR 3.4.0 through 3.9.1, when BGP is enabled, does not properly handle unrecognized transitive attributes, which allows remote attackers to cause a denial of service (peering reset) via a crafted prefix announcement, as demonstrated in the wild in August 2010 with attribute type code 99, aka Bug ID CSCti62211.
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.
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 DSL CPE devices running CBOS 2.4.4 and earlier allows remote attackers to cause a denial of service (hang or memory consumption) via (1) a large packet to the DHCP port, (2) a large packet to the Telnet port, or (3) a flood of large packets to the CPE, which causes the TCP/IP stack to consume large amounts of memory.
Cisco ONS15454 optical transport platform running ONS 3.1.0 to 3.2.0 allows remote attackers to cause a denial of service (reset) by sending IP packets with non-zero Type of Service (TOS) bits to the Timing Control Card (TCC) LAN interface.
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.
Cisco IP Phone (VoIP) models 7910, 7940, and 7960 allow remote attackers to cause a denial of service (crash) via malformed packets as demonstrated by (1) "jolt", (2) "jolt2", (3) "raped", (4) "hping2", (5) "bloop", (6) "bubonic", (7) "mutant", (8) "trash", and (9) "trash2."