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 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.

The High Availability (HA) subsystem in Cisco NX-OS on MDS 9000 devices allows remote attackers to cause a denial of service via crafted traffic, aka Bug ID CSCuo09129.

Cisco Identity Services Engine does not properly restrict the creation of guest accounts, which allows remote attackers to cause a denial of service (exhaustion of the account supply) via a series of requests within one session, aka Bug ID CSCue94287.

The hamgr service in the IPv6 Proxy Mobile (PM) implementation in Cisco StarOS 18.1.0.59776 on ASR 5000 devices allows remote attackers to cause a denial of service (service reload and call-processing outage) via malformed PM packets, aka Bug ID CSCut94711.

A vulnerability in the RESTCONF and NETCONF-YANG access control list (ACL) function of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload. The vulnerability is due to incorrect processing of the ACL that is tied to the RESTCONF or NETCONF-YANG feature. An attacker could exploit this vulnerability by accessing the device using RESTCONF or NETCONF-YANG. A successful exploit could allow an attacker to cause the device to reload, resulting in a denial of service (DoS) condition.

The Precision Video Engine component in Cisco Jabber for Windows and Cisco Virtualization Experience Media Engine allows remote attackers to cause a denial of service (process crash and call disconnection) via crafted RTP packets, aka Bug IDs CSCuh60706 and CSCue21117.

A vulnerability in the Cisco Umbrella Integration feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition, related to the OpenDNS software. The vulnerability is due to a logic error that exists when handling a malformed incoming packet, leading to access to an internal data structure after it has been freed. An attacker could exploit this vulnerability by sending crafted, malformed IP packets to an affected device. A successful exploit could allow the attacker to cause an affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvb86327.

A vulnerability in the egress packet processing functionality of the Cisco StarOS operating system for Cisco Aggregation Services Router (ASR) 5700 Series devices and Virtualized Packet Core (VPC) System Software could allow an unauthenticated, remote attacker to cause an interface on the device to cease forwarding packets. The device may need to be manually reloaded to clear this Interface Forwarding Denial of Service condition. The vulnerability is due to the failure to properly check that the length of a packet to transmit does not exceed the maximum supported length of the network interface card (NIC). An attacker could exploit this vulnerability by sending a crafted IP packet or a series of crafted IP fragments through an interface on the targeted device. A successful exploit could allow the attacker to cause the network interface to cease forwarding packets. This vulnerability could be triggered by either IPv4 or IPv6 network traffic. This vulnerability affects the following Cisco products when they are running the StarOS operating system and a virtual interface card is installed on the device: Aggregation Services Router (ASR) 5700 Series, Virtualized Packet Core-Distributed Instance (VPC-DI) System Software, Virtualized Packet Core-Single Instance (VPC-SI) System Software. Cisco Bug IDs: CSCvf32385.

A vulnerability in the TCP stack of Cisco SocialMiner could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition in the notification system. The vulnerability is due to faulty handling of new TCP connections to the affected application. An attacker could exploit this vulnerability by sending a malicious TCP packet to the vulnerable service. An exploit could allow the attacker to create a DoS condition by interrupting certain phone services. A manual restart of the service may be required to restore full functionalities. Cisco Bug IDs: CSCvh48368.

Multiple vulnerabilities in the Application Layer Protocol Inspection feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerabilities are due to logical errors during traffic inspection. An attacker could exploit these vulnerabilities by sending a high volume of malicious traffic across an affected device. An exploit could allow the attacker to cause a deadlock condition, resulting in a reload of an affected device. These vulnerabilities affect Cisco ASA Software and Cisco FTD Software configured for Application Layer Protocol Inspection running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4100 Series Security Appliance, Firepower 9300 ASA Security Module, FTD Virtual (FTDv). Cisco Bug IDs: CSCve61540, CSCvh23085, CSCvh95456.

The Cisco Unified IP Conference Station 7937G allows remote attackers to cause a denial of service (networking outage) via a flood of TCP packets, aka Bug ID CSCuh42052.

A vulnerability in the Session Initiation Protocol (SIP) call-handling functionality of Cisco IP Phone 7800 Series phones and Cisco IP Phone 8800 Series phones could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected phone. The vulnerability is due to incomplete input validation of SIP Session Description Protocol (SDP) parameters by the SDP parser of an affected phone. An attacker could exploit this vulnerability by sending a malformed SIP packet to an affected phone. A successful exploit could allow the attacker to cause all active phone calls on the affected phone to be dropped while the SIP process on the phone unexpectedly restarts, resulting in a DoS condition. Cisco Bug IDs: CSCvf40066.

A vulnerability in the netconf interface of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on affected system. The vulnerability is due to improper handling of malformed requests processed by the netconf process. An attacker could exploit this vulnerability by sending malicious requests to the affected software. An exploit could allow the attacker to cause the targeted process to restart, resulting in a DoS condition on the affected system. Cisco Bug IDs: CSCvg95792.

The HTTP/2 protocol allows a denial of service (server resource consumption) because request cancellation can reset many streams quickly, as exploited in the wild in August through October 2023.

A vulnerability in the DHCP option 82 encapsulation functionality of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of option 82 information that it receives in DHCP Version 4 (DHCPv4) packets from DHCP relay agents. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCuh91645.

A vulnerability in the Session Initiation Protocol (SIP) ingress packet processing of Cisco Unified IP Phone software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to a lack of flow-control mechanisms in the software. An attacker could exploit this vulnerability by sending high volumes of SIP INVITE traffic to the targeted device. Successful exploitation could allow the attacker to cause a disruption of services on the targeted IP phone. Cisco Bug IDs: CSCve10064, CSCve14617, CSCve14638, CSCve14683, CSCve20812, CSCve20926, CSCve20945.

A vulnerability in the file descriptor handling of Cisco TelePresence Video Communication Server (VCS) Expressway could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to exhaustion of file descriptors while processing a high volume of traffic. An attacker could exploit this vulnerability by establishing a high number of concurrent TCP connections to the vulnerable system. An exploit could allow the attacker to cause a restart in a specific process, resulting in a temporary interruption of service. Cisco Bug IDs: CSCvh77056, CSCvh77058, CSCvh95264.

A vulnerability in the IPsec Manager of Cisco StarOS for Cisco Aggregation Services Router (ASR) 5000 Series Routers and Virtualized Packet Core (VPC) System Software could allow an unauthenticated, remote attacker to terminate all active IPsec VPN tunnels and prevent new tunnels from being established, resulting in a denial of service (DoS) condition. The vulnerability is due to improper processing of corrupted Internet Key Exchange Version 2 (IKEv2) messages. An attacker could exploit this vulnerability by sending crafted IKEv2 messages toward an affected router. A successful exploit could allow the attacker to cause the ipsecmgr service to reload. A reload of this service could cause all IPsec VPN tunnels to be terminated and prevent new tunnels from being established until the service has restarted, resulting in a DoS condition. This vulnerability affects the following Cisco products when they are running Cisco StarOS: Cisco Aggregation Services Router (ASR) 5000 Series Routers, Virtualized Packet Core (VPC) System Software. Cisco Bug IDs: CSCve29605.

A vulnerability in the Cisco IOS Software and Cisco IOS XE Software function that restores encapsulated option 82 information in DHCP Version 4 (DHCPv4) packets could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a Relay Reply denial of service (DoS) condition. The vulnerability exists because the affected software performs incomplete input validation of encapsulated option 82 information that it receives in DHCPOFFER messages from DHCPv4 servers. An attacker could exploit this vulnerability by sending a crafted DHCPv4 packet to an affected device, which the device would then forward to a DHCPv4 server. When the affected software processes the option 82 information that is encapsulated in the response from the server, an error could occur. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvg62754.

A vulnerability in the Real-Time Transport Protocol (RTP) bitstream processing of the Cisco Meeting Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient input validation of incoming RTP bitstreams. An attacker could exploit this vulnerability by sending a crafted RTP bitstream to an affected Cisco Meeting Server. A successful exploit could allow the attacker to deny audio and video services by causing media process crashes resulting in a DoS condition on the affected product. This vulnerability affects Cisco Meeting Server deployments that are running Cisco Meeting Server Software Releases 2.0, 2.1, 2.2, and 2.3. Cisco Bug IDs: CSCve79693, CSCvf91393, CSCvg64656, CSCvh30725, CSCvi86363.

A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) protocol component of Cisco Wireless LAN Controller (WLC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to improper input validation on fields within CAPWAP Discovery Request packets by the affected device. An attacker could exploit this vulnerability by sending malicious CAPWAP Discovery Request packets to the Cisco WLC Software. A successful exploit could allow the attacker to cause the Cisco WLC Software to disconnect associated access points (APs). While the APs disconnect and reconnect, service will be unavailable for a brief period of time, resulting in a DoS condition.

Cisco ACE A2(3.6) allows log retention DoS.

Memory leak in the SNMP process in Cisco IOS XR allows remote attackers to cause a denial of service (memory consumption or process reload) by sending many port-162 UDP packets, aka Bug ID CSCug80345.

The C-Series Rack Server component 1.4 in Cisco Unified Computing System (UCS) does not properly restrict inbound access to ports, which allows remote attackers to cause a denial of service (Integrated Management Controller reboot or hang) via crafted packets, as demonstrated by nmap, aka Bug ID CSCtx19850.

TMSSNMPService.exe in TelePresence Manager in Cisco TelePresence Management Suite (TMS) on 64-bit platforms allows remote attackers to cause a denial of service (process crash) via SNMP traps, aka Bug ID CSCue00028.

Cisco NX-OS on the Nexus 1000V does not assign the proper priority to heartbeat messages from a Virtual Ethernet Module (VEM) to a Virtual Supervisor Module (VSM), which allows remote attackers to cause a denial of service (false VEM unavailability report) via a flood of UDP packets, aka Bug ID CSCud14840.

Cisco Carrier Routing System (CRS) allows remote attackers to cause a denial of service (packet loss) via short malformed packets that trigger inefficient processing, aka Bug ID CSCud79136.

Cisco Tivoli Business Service Manager (TBSM) in Hosted Collaboration Mediation (HCM) in Cisco Hosted Collaboration Solution allows remote attackers to cause a denial of service (temporary service hang) by sending many TCP packets to certain ports, aka Bug ID CSCue03703.

Cisco Wireless LAN Controller (WLC) devices do not properly address the resource consumption of terminated TELNET sessions, which allows remote attackers to cause a denial of service (TELNET outage) by making many TELNET connections and improperly ending these connections, aka Bug ID CSCug35507.

The NAT process on Cisco Adaptive Security Appliances (ASA) devices allows remote attackers to cause a denial of service (connections-table memory consumption) via crafted packets, aka Bug ID CSCue46386.

The traffic engineering (TE) processing subsystem in Cisco IOS XR allows remote attackers to cause a denial of service (process restart) via crafted TE packets, aka Bug ID CSCue04000.

Cisco Unified Communications Domain Manager allows remote attackers to cause a denial of service (CPU consumption) via a flood of malformed UDP packets, aka Bug ID CSCug47057.

Memory leak in Cisco Unity Connection 9.x allows remote attackers to cause a denial of service (memory consumption and process crash) by sending many TCP requests, aka Bug ID CSCud59736.

Cisco Unified Communications Manager (CUCM) does not properly limit the rate of authentication attempts, which allows remote attackers to cause a denial of service (application slowdown) via a series of requests, aka Bug ID CSCud39515.

A vulnerability in the packet processing functionality of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to inefficient memory management. An attacker could exploit this vulnerability by sending a large number of TCP packets to a specific port on an affected device. A successful exploit could allow the attacker to exhaust system memory, which could cause the device to reload unexpectedly. No manual intervention is needed to recover the device after it has reloaded.

A vulnerability in the host input API daemon of Cisco Firepower Management Center (FMC) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper certificate validation. An attacker could exploit this vulnerability by sending a crafted data stream to the host input daemon of the affected device. A successful exploit could allow the attacker to cause the host input daemon to restart. The attacker could use repeated attacks to cause the daemon to continuously reload, creating a DoS condition for the API.

OpenSSL 0.9.6k allows remote attackers to cause a denial of service (crash via large recursion) via malformed ASN.1 sequences.

A vulnerability in the UDP processing code of Cisco IOS 15.1, 15.2, and 15.4 and IOS XE 3.14 through 3.18 could allow an unauthenticated, remote attacker to cause the input queue of an affected system to hold UDP packets, causing an interface queue wedge and a denial of service (DoS) condition. The vulnerability is due to Cisco IOS Software application changes that create UDP sockets and leave the sockets idle without closing them. An attacker could exploit this vulnerability by sending UDP packets with a destination port of 0 to an affected device. A successful exploit could allow the attacker to cause UDP packets to be held in the input interfaces queue, resulting in a DoS condition. The input interface queue will stop holding UDP packets when it receives 250 packets. Cisco Bug IDs: CSCup10024, CSCva55744, CSCva95506.

Multiple vulnerabilities in the Zone-Based Firewall feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload or stop forwarding traffic through the firewall. The vulnerabilities are due to incomplete handling of Layer 4 packets through the device. An attacker could exploit these vulnerabilities by sending a certain sequence of traffic patterns through the device. A successful exploit could allow the attacker to cause the device to reload or stop forwarding traffic through the firewall, resulting in a denial of service. For more information about these vulnerabilities, see the Details section of this advisory.

Cisco Sourcefire Snort 3.0 before build 233 mishandles Ether Type Validation. Since valid ether type and IP protocol numbers do not overlap, Snort++ stores all protocol decoders in a single array. That makes it possible to craft packets that have IP protocol numbers in the ether type field which will confuse the Snort++ decoder. For example, an eth:llc:snap:icmp6 packet will cause a crash because there is no ip6 header with which to calculate the icmp6 checksum. Affected decoders include gre, llc, trans_bridge, ciscometadata, linux_sll, and token_ring. The fix adds a check in the packet manager to validate the ether type before indexing the decoder array. An out of range ether type will raise 116:473.

Cisco Sourcefire Snort 3.0 before build 233 has a Buffer Overread related to use of a decoder array. The size was off by one making it possible to read past the end of the array with an ether type of 0xFFFF. Increasing the array size solves this problem.

A vulnerability in the web-based management interface of Cisco AsyncOS for Cisco Email Security Appliance (ESA), Cisco Web Security Appliance (WSA), and Cisco Content Security Management Appliance (SMA) could allow an unauthenticated remote attacker to cause high CPU usage on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper validation of specific HTTP request headers. An attacker could exploit this vulnerability by sending a malformed HTTP request to an affected device. A successful exploit could allow the attacker to trigger a prolonged status of high CPU utilization relative to the GUI process(es). Upon successful exploitation of this vulnerability, an affected device will still be operative, but its response time and overall performance may be degraded.

A vulnerability in the ingress processing of fragmented TCP packets by Cisco Wide Area Application Services (WAAS) could allow an unauthenticated, remote attacker to cause the WAASNET process to restart unexpectedly, causing a denial of service (DoS) condition. More Information: CSCvc57428. Known Affected Releases: 6.3(1). Known Fixed Releases: 6.3(0.143) 6.2(3c)6 6.2(3.22).

Multiple Cisco products are affected by a vulnerability in the way the Snort detection engine processes ICMP traffic that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper memory resource management while the Snort detection engine is processing ICMP packets. An attacker could exploit this vulnerability by sending a series of ICMP packets through an affected device. A successful exploit could allow the attacker to exhaust resources on the affected device, causing the device to reload.

A vulnerability in the Border Gateway Protocol (BGP) processing functionality of the Cisco StarOS operating system for Cisco ASR 5000 Series Routers and Cisco Virtualized Packet Core (VPC) Software could allow an unauthenticated, remote attacker to cause the BGP process on an affected system to reload, resulting in a denial of service (DoS) condition. This vulnerability affects the following products if they are running the Cisco StarOS operating system and BGP is enabled for the system: Cisco ASR 5000 Series Routers and Cisco Virtualized Packet Core Software. More Information: CSCvc44968. Known Affected Releases: 16.4.1 19.1.0 21.1.0 21.1.M0.65824. Known Fixed Releases: 21.3.A0.65902 21.2.A0.65905 21.1.b0.66164 21.1.V0.66014 21.1.R0.65898 21.1.M0.65894 21.1.0.66030 21.1.0.

A vulnerability in the web-based management interface of Cisco Small Business 200 Series Smart Switches, Cisco Small Business 300 Series Managed Switches, and Cisco Small Business 500 Series Stackable Managed Switches could allow an unauthenticated, remote attacker to render the web-based management interface unusable, resulting in a denial of service (DoS) condition. This vulnerability is due to improper validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to cause a permanent invalid redirect for requests sent to the web-based management interface of the device, resulting in a DoS condition.