A vulnerability in the Protocol Independent Multicast (PIM) feature for IPv6 networks (PIM6) of Cisco NX-OS 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 error handling when processing inbound PIM6 packets. An attacker could exploit this vulnerability by sending multiple crafted PIM6 packets to an affected device. A successful exploit could allow the attacker to cause the PIM6 application to leak system memory. Over time, this memory leak could cause the PIM6 application to stop processing legitimate PIM6 traffic, leading to a DoS condition on the affected device.

A vulnerability in the hardware crypto driver of Cisco IOS XE Software for Cisco 4300 Series Integrated Services Routers and Cisco Catalyst 9800-L Wireless Controllers could allow an unauthenticated, remote attacker to disconnect legitimate IPsec VPN sessions to an affected device. The vulnerability is due to insufficient verification of authenticity of received Encapsulating Security Payload (ESP) packets. An attacker could exploit this vulnerability by tampering with ESP cleartext values as a man-in-the-middle.

The IGMP implementation on Cisco Wireless LAN Controller (WLC) devices 4.x, 5.x, 6.x, 7.0 before 7.0.250.0, 7.1, 7.2, and 7.3, when IGMPv3 Snooping is enabled, allows remote attackers to cause a denial of service (memory over-read and device restart) via a crafted field in an IGMPv3 message, aka Bug ID CSCuh33240.

A vulnerability in the SSL/TLS inspection of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series firewalls could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper input validation for certain fields of specific SSL/TLS messages. An attacker could exploit this vulnerability by sending a malformed SSL/TLS message through an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. No manual intervention is needed to recover the device after it has reloaded.

A vulnerability in the Umbrella Connector component of Cisco IOS XE Software for Cisco Catalyst 9200 Series Switches could allow an unauthenticated, remote attacker to trigger a reload, resulting in a denial of service condition on an affected device. The vulnerability is due to insufficient error handling when parsing DNS requests. An attacker could exploit this vulnerability by sending a series of malicious DNS requests to an Umbrella Connector client interface of an affected device. A successful exploit could allow the attacker to cause a crash of the iosd process, which triggers a reload of the affected device.

A vulnerability in the Session Initiation Protocol (SIP) UDP throttling process of Cisco Unified Communications Manager (Cisco Unified CM) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient rate limiting protection. An attacker could exploit this vulnerability by sending the affected device a high rate of SIP messages. An exploit could allow the attacker to cause the device to reload unexpectedly. The device and services will restart automatically. This vulnerability affects Cisco Unified Communications Manager (CallManager) releases prior to the first fixed release; the following list indicates the first minor release that includes the fix for this vulnerability: 10.5.2.14900-16 11.0.1.23900-5 11.5.1.12900-2. Cisco Bug IDs: CSCuz72455.

A vulnerability in the Live Data server of Cisco Unified Contact Center Enterprise could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability exists because the affected software improperly manages resources when processing inbound Live Data traffic. An attacker could exploit this vulnerability by sending multiple crafted Live Data packets to an affected device. A successful exploit could cause the affected device to run out of buffer resources, which could result in a stack overflow and cause the affected device to reload, resulting in a DoS condition. Note: The Live Data port in Cisco Unified Contact Center Enterprise devices allows only a single TCP connection. To exploit this vulnerability, an attacker would have to send crafted packets to an affected device before a legitimate Live Data client establishes a connection.

A vulnerability in the DHCP code for the Zero Touch Provisioning feature of Cisco ASR 920 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to a format string vulnerability when processing a crafted DHCP packet for Zero Touch Provisioning. An attacker could exploit this vulnerability by sending a specially crafted DHCP packet to an affected device. An exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition. This vulnerability affects Cisco ASR 920 Series Aggregation Services Routers that are running an affected release of Cisco IOS XE Software (3.13 through 3.18) and are listening on the DHCP server port. By default, the devices do not listen on the DHCP server port. Cisco Bug IDs: CSCuy56385.

A vulnerability in the Secure Login Enhancements capability of Cisco Nexus 1000V Switch for VMware vSphere could allow an unauthenticated, remote attacker to cause an affected Nexus 1000V Virtual Supervisor Module (VSM) to become inaccessible to users through the CLI. The vulnerability is due to improper resource allocation during failed CLI login attempts when login parameters that are part of the Secure Login Enhancements capability are configured on an affected device. An attacker could exploit this vulnerability by performing a high amount of login attempts against the affected device. A successful exploit could cause the affected device to become inaccessible to other users, resulting in a denial of service (DoS) condition requiring a manual power cycle of the VSM to recover.

A vulnerability in the Event Management Service daemon (emsd) of Cisco IOS XR routers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the affected device. The vulnerability is due to improper handling of gRPC requests. An attacker could exploit this vulnerability by repeatedly sending unauthenticated gRPC requests to the affected device. A successful exploit could allow the attacker to crash the device in such a manner that manual intervention is required to recover. This vulnerability affects all Cisco IOS XR platforms that are running release 6.1.1 of Cisco IOS XR Software when the gRPC service is enabled on the device. The gRPC service is not enabled by default. Cisco Bug IDs: CSCvb14441.

A vulnerability in the detection engine reassembly of Secure Sockets Layer (SSL) packets for Cisco Firepower System Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition because the Snort process consumes a high level of CPU resources. Affected Products: This vulnerability affects Cisco Firepower System Software running software releases 6.0.0, 6.1.0, 6.2.0, or 6.2.1 when the device is configured with an SSL policy that has at least one rule specifying traffic decryption. More Information: CSCvc58563. Known Affected Releases: 6.0.0 6.1.0 6.2.0 6.2.1.

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 Unity 4.x before 4.2(1)ES161, 5.x before 5.0(1)ES53, and 7.x before 7.0(2)ES8, when using anonymous authentication (aka native Unity authentication), allows remote attackers to cause a denial of service (session exhaustion) via a large number of connections.

A vulnerability in the rate limiter for Bidirectional Forwarding Detection (BFD) traffic of Cisco NX-OS Software for Cisco Nexus 9000 Series Switches could allow an unauthenticated, remote attacker to cause BFD traffic to be dropped on an affected device. This vulnerability is due to a logic error in the BFD rate limiter functionality. An attacker could exploit this vulnerability by sending a crafted stream of traffic through the device. A successful exploit could allow the attacker to cause BFD traffic to be dropped, resulting in BFD session flaps. BFD session flaps can cause route instability and dropped traffic, resulting in a denial of service (DoS) condition. This vulnerability applies to both IPv4 and IPv6 traffic.

Unspecified vulnerability in the VLAN Trunking Protocol (VTP) implementation on Cisco IOS and CatOS, when the VTP operating mode is not transparent, allows remote attackers to cause a denial of service (device reload or hang) via a crafted VTP packet sent to a switch interface configured as a trunk port.

The TCP implementation in (1) Linux, (2) platforms based on BSD Unix, (3) Microsoft Windows, (4) Cisco products, and probably other operating systems allows remote attackers to cause a denial of service (connection queue exhaustion) via multiple vectors that manipulate information in the TCP state table, as demonstrated by sockstress.

Cisco IOS 12.0 through 12.4 on Gigabit Switch Router (GSR) devices (aka 12000 Series routers) allows remote attackers to cause a denial of service (device crash) via a malformed Protocol Independent Multicast (PIM) packet.

Unspecified vulnerability in the Session Initiation Protocol (SIP) implementation in Cisco IOS 12.2 through 12.4 and Unified Communications Manager 4.1 through 6.1, when VoIP is configured, allows remote attackers to cause a denial of service (device or process reload) via unspecified valid SIP messages, aka Cisco Bug ID CSCsm46064, a different vulnerability than CVE-2008-3800 and CVE-2008-3802.

The TCP implementation in Cisco IOS does not properly implement the transitions from the ESTABLISHED state to the CLOSED state, which allows remote attackers to cause a denial of service (flood of ACK packets) via a crafted series of ACK and FIN packets, aka Bug ID CSCtz14399.

Unspecified vulnerability in the Multi Protocol Label Switching (MPLS) Forwarding Infrastructure (MFI) in Cisco IOS 12.2 and 12.4 allows remote attackers to cause a denial of service (memory corruption) via crafted packets for which the software path is used.

The TFTP server in Cisco IOS 12.2(44)SQ1, 12.2(33)XN1, 12.4(25e)JAM1, 12.4(25e)JAO5m, 12.4(23)JY, 15.0(2)ED1, 15.0(2)EY3, 15.1(3)SVF4a, and 15.2(2)JB1 and IOS XE 2.5.x, 2.6.x, 3.1.xS, 3.2.xS, 3.3.xS, 3.4.xS, and 3.5.xS before 3.6.0S; 3.1.xSG, 3.2.xSG, and 3.3.xSG before 3.4.0SG; 3.2.xSE before 3.3.0SE; 3.2.xXO before 3.3.0XO; 3.2.xSQ; 3.3.xSQ; and 3.4.xSQ allows remote attackers to cause a denial of service (device hang or reload) via multiple requests that trigger improper memory management, aka Bug ID CSCts66733.

Cisco IOS 12.4, when IOS firewall Application Inspection Control (AIC) with HTTP Deep Packet Inspection is enabled, allows remote attackers to cause a denial of service (device reload) via a malformed HTTP transit packet.

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.

Cisco Unified Communications Manager (Unified CM) 8.5(x) and 8.6(x) before 8.6(2a)su3 and 9.x before 9.1(1) does not properly restrict the rate of SIP packets, which allows remote attackers to cause a denial of service (memory and CPU consumption, and service disruption) via a flood of UDP packets to port 5060, aka Bug ID CSCub35869.

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.

Unspecified vulnerability in the Session Initiation Protocol (SIP) implementation in Cisco IOS 12.2 through 12.4 and Unified Communications Manager 4.1 through 6.1, when VoIP is configured, allows remote attackers to cause a denial of service (device or process reload) via unspecified valid SIP messages, aka Cisco Bug ID CSCsu38644, a different vulnerability than CVE-2008-3801 and CVE-2008-3802.

Unspecified vulnerability in the Session Initiation Protocol (SIP) implementation in Cisco IOS 12.2 through 12.4, when VoIP is configured, allows remote attackers to cause a denial of service (device reload) via unspecified valid SIP messages, aka Cisco bug ID CSCsk42759, a different vulnerability than CVE-2008-3800 and CVE-2008-3801.

Memory leak in the crypto functionality in Cisco Adaptive Security Appliance (ASA) 5500 devices 7.2 before 7.2(4)2, 8.0 before 8.0(3)14, and 8.1 before 8.1(1)4, when configured as a clientless SSL VPN endpoint, allows remote attackers to cause a denial of service (memory consumption and VPN hang) via a crafted SSL or HTTP packet, aka Bug ID CSCso66472.

Cisco PIX and Adaptive Security Appliance (ASA) 5500 devices 7.2 before 7.2(4)2, 8.0 before 8.0(3)14, and 8.1 before 8.1(1)4, when configured as a client VPN endpoint, do not properly process IPSec client authentication, which allows remote attackers to cause a denial of service (device reload) via a crafted authentication attempt, aka Bug ID CSCso69942.

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 DHCPv6 feature of the Cisco Nexus 9000 Series Fabric Switches in Application-Centric Infrastructure (ACI) Mode could allow an unauthenticated, remote attacker to cause the device to run low on system memory, which could result in a Denial of Service (DoS) condition on an affected system. The vulnerability is due to improper memory management when DHCPv6 packets are received on an interface of the targeted device. An attacker could exploit this vulnerability by sending a high number of malicious DHCPv6 packets to be processed by an affected device. A successful exploit could allow the attacker to cause the system to run low on memory, which could cause an eventual reboot of an affected device. The vulnerability only applies to IPv6 protocol packets and not for IPv4 protocol packets. This vulnerability affects Cisco Nexus 9000 Series Fabric Switches in ACI Mode running software version 13.0(1k). The vulnerability can only be exploited when unicast routing is enabled on the Bridge Domain (BD). DHCP and DHCP relay do not have to be configured for the vulnerability to be exploited. Cisco Bug IDs: CSCvg38918.

A vulnerability in the Forwarding Information Base (FIB) code of Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, network attacker to cause a denial of service (DoS) condition. The vulnerability is due to a limitation in the way the FIB is internally representing recursive routes. An attacker could exploit this vulnerability by injecting routes into the routing protocol that have a specific recursive pattern. The attacker must be in a position on the network that provides the ability to inject a number of recursive routes with a specific pattern. An exploit could allow the attacker to cause an affected device to reload, creating a DoS condition. Cisco Bug IDs: CSCva91655.

The Location Bandwidth Manager (LBM) Intracluster-communication feature in Cisco Unified Communications Manager (CUCM) 9.x before 9.1(1) does not require authentication from the remote LBM Hub node, which allows remote attackers to conduct cache-poisoning attacks against transaction records, and cause a denial of service (bandwidth-pool consumption and call outage), via unspecified vectors, aka Bug ID CSCub28920.

Cisco IOS XE 3.2 through 3.4 before 3.4.2S, and 3.5, on 1000 series Aggregation Services Routers (ASR), when bridge domain interface (BDI) is enabled, allows remote attackers to cause a denial of service (card reload) via packets that are not properly handled during the processing of encapsulation, aka Bug ID CSCtt11558.

The virtual private dial-up network (VPDN) component in Cisco IOS before 12.3 allows remote attackers to cause a denial of service (resource exhaustion) via a series of PPTP sessions, related to the persistence of interface descriptor block (IDB) data structures after process termination, aka bug ID CSCdv59309.

A vulnerability in the Session Initiation Protocol (SIP) on the Cisco TelePresence Video Communication Server (VCS) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on the targeted appliance. The vulnerability is due to excessive SIP traffic sent to the device. An attacker could exploit this vulnerability by transmitting large volumes of SIP traffic to the VCS. An exploit could allow the attacker to cause a complete DoS condition on the targeted system. Cisco Bug IDs: CSCve32897.

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 logging configuration of Secure Sockets Layer (SSL) policies for Cisco FirePOWER System Software 5.3.0 through 6.2.2 could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition due to high consumption of system resources. The vulnerability is due to the logging of certain TCP packets by the affected software. An attacker could exploit this vulnerability by sending a flood of crafted TCP packets to an affected device. A successful exploit could allow the attacker to cause a DoS condition. The success of an exploit is dependent on how an administrator has configured logging for SSL policies for a device. This vulnerability affects Cisco FirePOWER System Software that is configured to log connections by using SSL policy default actions. Cisco Bug IDs: CSCvd07072.

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 TCP throttling process of Cisco UCS C-Series Rack Servers 3.0(0.234) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient rate-limiting protection. An attacker could exploit this vulnerability by sending a high rate of TCP SYN packets to a specific TCP listening port on an affected device. An exploit could allow the attacker to cause a specific TCP listening port to stop accepting new connections, resulting in a DoS condition. Cisco Bug IDs: CSCva65544.

Multiple Cisco products are affected by a vulnerability in Snort rules 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 handling of the Block with Reset or Interactive Block with Reset actions if a rule is configured without proper constraints. An attacker could exploit this vulnerability by sending a crafted IP packet to the affected device. A successful exploit could allow the attacker to cause through traffic to be dropped. Note: Only products with Snort3 configured and either a rule with Block with Reset or Interactive Block with Reset actions configured are vulnerable. Products configured with Snort2 are not vulnerable.

A vulnerability in the TCP throttling process for Cisco IoT Field Network Director (IoT-FND) could allow an unauthenticated, remote attacker to cause the system to consume additional memory, eventually forcing the device to restart, aka Memory Exhaustion. The vulnerability is due to insufficient rate-limiting protection. An attacker could exploit this vulnerability by sending a high rate of TCP packets to a specific group of open listening ports on a targeted device. An exploit could allow the attacker to cause the system to consume additional memory. If enough available memory is consumed, the system will restart, creating a temporary denial of service (DoS) condition. The DoS condition will end after the device has finished the restart process. This vulnerability affects the following Cisco products: Connected Grid Network Management System, if running a software release prior to IoT-FND Release 4.0; IoT Field Network Director, if running a software release prior to IoT-FND Release 4.0. Cisco Bug IDs: CSCvc77164.

A vulnerability in the Control and Provisioning of Wireless Access Points (CAPWAP) Discovery Request parsing functionality of Cisco Wireless LAN Controllers could allow an unauthenticated, remote attacker to cause an affected device to restart unexpectedly, resulting in a denial of service (DoS) condition. The vulnerability is due to incomplete input validation of fields in CAPWAP Discovery Request packets by the affected device. An attacker could exploit this vulnerability by sending crafted CAPWAP Discovery Request packets to an affected device. A successful exploit could allow the attacker to cause the affected device to restart unexpectedly, resulting in a DoS condition. Cisco Bug IDs: CSCvb95842.

Memory leak in the virtual private dial-up network (VPDN) component in Cisco IOS before 12.3 allows remote attackers to cause a denial of service (memory consumption) via a series of PPTP sessions, related to "dead memory" that remains allocated after process termination, aka bug ID CSCsj58566.