A vulnerability in the IP fragment-handling implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a memory leak on an affected device. This memory leak could prevent traffic from being processed through the device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper error handling when specific failures occur during IP fragment reassembly. An attacker could exploit this vulnerability by sending crafted, fragmented IP traffic to a targeted device. A successful exploit could allow the attacker to continuously consume memory on the affected device and eventually impact traffic, resulting in a DoS condition. The device could require a manual reboot to recover from the DoS condition. Note: This vulnerability applies to both IP Version 4 (IPv4) and IP Version 6 (IPv6) traffic.

A vulnerability in Cisco Aironet Access Points (APs) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) on an affected device. The vulnerability is due to improper resource management while processing specific packets. An attacker could exploit this vulnerability by sending a series of crafted UDP packets to a specific port on an affected device. A successful exploit could either allow the attacker to tear down the connection between the AP and the wireless LAN controller, resulting in the affected device not being able to process client traffic, or cause the vulnerable device to reload, triggering a DoS condition. After the attack, the affected device should automatically recover its normal functions without manual intervention.

A vulnerability in the web interface of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. The vulnerability is due to a lack of proper input validation of HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. An exploit could allow the attacker to cause a DoS condition. Note: This vulnerability applies to IP Version 4 (IPv4) and IP Version 6 (IPv6) HTTP traffic.

A vulnerability in the Split DNS feature 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 occurs because the regular expression (regex) engine that is used with the Split DNS feature of affected releases may time out when it processes the DNS name list configuration. An attacker could exploit this vulnerability by trying to resolve an address or hostname that the affected device handles. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

A vulnerability in the local management (local-mgmt) CLI of Cisco UCS Manager Software could allow an authenticated, local attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper handling of CLI command parameters. An attacker could exploit this vulnerability by executing specific commands on the local-mgmt CLI on an affected device. A successful exploit could allow the attacker to cause internal system processes to fail to terminate properly, which could result in a buildup of stuck processes and lead to slowness in accessing the UCS Manager CLI and web UI. A sustained attack may result in a restart of internal UCS Manager processes and a temporary loss of access to the UCS Manager CLI and web UI.

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.

Multiple vulnerabilities in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to either immediately crash the Internet Group Management Protocol (IGMP) process or make it consume available memory and eventually crash. The memory consumption may negatively impact other processes that are running on the device. These vulnerabilities are due to the incorrect handling of IGMP packets. An attacker could exploit these vulnerabilities by sending crafted IGMP traffic to an affected device. A successful exploit could allow the attacker to immediately crash the IGMP process or cause memory exhaustion, resulting in other processes becoming unstable. These processes may include, but are not limited to, interior and exterior routing protocols. Cisco will release software updates that address these vulnerabilities.

A vulnerability in the VPN System Logging functionality for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a memory leak that can deplete system memory over time, which can cause unexpected system behaviors or device crashes. The vulnerability is due to the system memory not being properly freed for a VPN System Logging event generated when a VPN session is created or deleted. An attacker could exploit this vulnerability by repeatedly creating or deleting a VPN tunnel connection, which could leak a small amount of system memory for each logging event. A successful exploit could allow the attacker to cause system memory depletion, which can lead to a systemwide denial of service (DoS) condition. The attacker does not have any control of whether VPN System Logging is configured or not on the device, but it is enabled by default.

A vulnerability in the IPsec packet processor of Cisco IOS XR Software could allow an unauthenticated remote attacker to cause a denial of service (DoS) condition for IPsec sessions to an affected device. The vulnerability is due to improper handling of packets by the IPsec packet processor. An attacker could exploit this vulnerability by sending malicious ICMP error messages to an affected device that get punted to the IPsec packet processor. A successful exploit could allow the attacker to deplete IPsec memory, resulting in all future IPsec packets to an affected device being dropped by the device. Manual intervention is required to recover from this situation.

A vulnerability in the Secure Sockets Layer (SSL)/Transport Layer Security (TLS) handler of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to exhaust memory resources on the affected device, leading to a denial of service (DoS) condition. The vulnerability is due to improper resource management for inbound SSL/TLS connections. An attacker could exploit this vulnerability by establishing multiple SSL/TLS connections with specific conditions to the affected device. A successful exploit could allow the attacker to exhaust the memory on the affected device, causing the device to stop accepting new SSL/TLS connections and resulting in a DoS condition for services on the device that process SSL/TLS traffic. Manual intervention is required to recover an affected device.

A vulnerability in the resource handling system of Cisco NX-OS Software for Cisco MDS 9000 Series Multilayer Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper resource usage control. An attacker could exploit this vulnerability by sending traffic to the management interface (mgmt0) of an affected device at very high rates. An exploit could allow the attacker to cause unexpected behaviors such as high CPU usage, process crashes, or even full system reboots of an affected device.

A vulnerability in the Cisco Webex Teams client for Windows could allow an authenticated, remote attacker to cause the client to crash, resulting in a denial of service (DoS) condition. The attacker needs a valid developer account to exploit this vulnerability. The vulnerability is due to insufficient input validation when processing received adaptive cards. The attacker could exploit this vulnerability by sending an adaptive card with malicious content to an existing user of the Cisco Webex Teams client for Windows. A successful exploit could allow the attacker to cause the targeted user's client to crash continuously. This vulnerability was introduced in Cisco Webex Teams client for Windows Release 3.0.13131.

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 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.

Apache Log4j2 2.0-beta9 through 2.15.0 (excluding security releases 2.12.2, 2.12.3, and 2.3.1) JNDI features used in configuration, log messages, and parameters do not protect against attacker controlled LDAP and other JNDI related endpoints. An attacker who can control log messages or log message parameters can execute arbitrary code loaded from LDAP servers when message lookup substitution is enabled. From log4j 2.15.0, this behavior has been disabled by default. From version 2.16.0 (along with 2.12.2, 2.12.3, and 2.3.1), this functionality has been completely removed. Note that this vulnerability is specific to log4j-core and does not affect log4net, log4cxx, or other Apache Logging Services projects.

A vulnerability in a feature that monitors RADIUS requests on Cisco Identity Services Engine (ISE) Software could allow an unauthenticated, remote attacker to negatively affect the performance of an affected device. This vulnerability is due to insufficient management of system resources. An attacker could exploit this vulnerability by taking actions that cause Cisco ISE Software to receive specific RADIUS traffic. A successful and sustained exploit of this vulnerability could allow the attacker to cause reduced performance of the affected device, resulting in significant delays to RADIUS authentications. There are workarounds that address this vulnerability.

A vulnerability in Cisco Smart Software Manager On-Prem (SSM On-Prem) could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to incorrect handling of multiple simultaneous device registrations on Cisco SSM On-Prem. An attacker could exploit this vulnerability by sending multiple device registration requests to Cisco SSM On-Prem. A successful exploit could allow the attacker to cause a DoS condition on an affected device.

A vulnerability in the NETCONF over SSH feature of Cisco IOS XE Software could allow a low-privileged, authenticated, remote attacker to cause a denial of service condition (DoS) on an affected device. This vulnerability is due to insufficient resource management. An attacker could exploit this vulnerability by initiating a large number of NETCONF over SSH connections. A successful exploit could allow the attacker to exhaust resources, causing the device to reload and resulting in a DoS condition on an affected device.

A vulnerability in the Cisco Fabric Services over IP (CFSoIP) feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient validation of incoming CFSoIP packets. An attacker could exploit this vulnerability by sending crafted CFSoIP packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

A vulnerability in the DNS inspection handler of Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service condition (DoS) on an affected device. This vulnerability is due to a lack of proper processing of incoming requests. An attacker could exploit this vulnerability by sending crafted DNS requests at a high rate to an affected device. A successful exploit could allow the attacker to cause the device to stop responding, resulting in a DoS condition.

Memory leak in the connection-manager implementation in Cisco Adaptive Security Appliance (ASA) Software 9.1(.3) and earlier allows remote attackers to cause a denial of service (multi-protocol management outage) by making multiple management session requests, aka Bug ID CSCug33233.

Cisco Adaptive Security Appliance (ASA) Software 8.4(.6) and earlier, when using an unsupported configuration with overlapping criteria for filtering and inspection, allows remote attackers to cause a denial of service (traffic loop and device crash) via a packet that triggers multiple matches, aka Bug ID CSCui45606.

A vulnerability in the Secure Sockets Layer (SSL) packet reassembly functionality of the detection engine in Cisco Firepower System Software could allow an unauthenticated, remote attacker to cause the detection engine to consume excessive system memory on an affected device, which could cause a denial of service (DoS) condition. The vulnerability is due to the affected software improperly handling changes to SSL connection states. An attacker could exploit this vulnerability by sending crafted SSL connections through an affected device. A successful exploit could allow the attacker to cause the detection engine to consume excessive system memory on the affected device, which could cause a DoS condition. The device may need to be reloaded manually to recover from this condition. This vulnerability affects Cisco Firepower System Software Releases 6.0.0 and later, running on any of the following Cisco products: Adaptive Security Appliance (ASA) 5500-X Series Firewalls with FirePOWER Services, Adaptive Security Appliance (ASA) 5500-X Series Next-Generation Firewalls, Advanced Malware Protection (AMP) for Networks, 7000 Series Appliances, Advanced Malware Protection (AMP) for Networks, 8000 Series Appliances, Firepower 4100 Series Appliances, FirePOWER 7000 Series Appliances, FirePOWER 8000 Series Appliances, Firepower 9300 Series Security Appliances, Firepower Threat Defense for Integrated Services Routers (ISRs), Firepower Threat Defense Virtual for VMware, Industrial Security Appliance 3000, Sourcefire 3D System Appliances. Cisco Bug IDs: CSCve23031.

Memory leak 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 (memory consumption and voice-service outage) via unspecified valid SIP messages.

A vulnerability in the Cisco Aironet Series Access Points (APs) software could allow an authenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. The vulnerability is due to a deadlock condition that may occur when an affected AP attempts to dequeue aggregated traffic that is destined to an attacker-controlled wireless client. An attacker who can successfully transition between multiple Service Set Identifiers (SSIDs) hosted on the same AP while replicating the required traffic patterns could trigger the deadlock condition. A watchdog timer that detects the condition will trigger a reload of the device, resulting in a DoS condition while the device restarts.

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 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 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 web-based management interface of Cisco SD-WAN vManage Software could allow an authenticated, remote attacker to consume excessive system memory and cause a denial of service (DoS) condition on an affected system. The vulnerability is due to inefficient memory management. An attacker could exploit this vulnerability by sending a large number of crafted HTTP requests to the affected web-based management interface. A successful exploit could allow the attacker to exhaust system memory, which could cause the system to stop processing new connections and could result in a DoS condition.

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 SSL/TLS message handler for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because incoming SSL/TLS packets are not properly processed. An attacker could exploit this vulnerability by sending a crafted SSL/TLS packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

A vulnerability in the Internet Key Exchange Version 2 (IKEv2) implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to trigger a denial of service (DoS) condition on an affected device. This vulnerability is due to improper control of a resource. An attacker with the ability to spoof a trusted IKEv2 site-to-site VPN peer and in possession of valid IKEv2 credentials for that peer could exploit this vulnerability by sending malformed, authenticated IKEv2 messages to an affected device. A successful exploit could allow the attacker to trigger a reload of the device.

A vulnerability in the malware detection functionality in Cisco Advanced Malware Protection (AMP) in Cisco AsyncOS Software for Cisco Email Security Appliances (ESAs) could allow an unauthenticated remote attacker to exhaust resources on an affected device. The vulnerability is due to insufficient control over system memory allocation. An attacker could exploit this vulnerability by sending a crafted email through the targeted device. A successful exploit could allow the attacker to cause an email attachment that contains malware to be delivered to a user and cause email processing delays.

A vulnerability in the Simple Network Management Protocol (SNMP) subsystem of Cisco Wireless LAN Controllers could allow an authenticated, remote attacker to cause an affected device to restart, resulting in a denial of service (DoS) condition. The vulnerability is due to a memory leak that occurs on an affected device after the device fails to deallocate a buffer that is used when certain MIBs are polled. An attacker who knows the SNMP Version 2 SNMP Read string or has valid SNMP Version 3 credentials for an affected device could repeatedly poll the affected MIB object IDs (OIDs) and consume available memory on the device. When memory is sufficiently depleted on the device, the device will restart, resulting in a DoS condition. Cisco Bug IDs: CSCvc71674.

A vulnerability in SSL traffic decryption for Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause depletion of system memory, aka a Firepower Detection Engine SSL Decryption Memory Consumption Denial of Service vulnerability. If this memory leak persists over time, a denial of service (DoS) condition could develop because traffic can cease to be forwarded through the device. The vulnerability is due to an error in how the Firepower Detection Snort Engine handles SSL traffic decryption and notifications to and from the Adaptive Security Appliance (ASA) handler. An attacker could exploit this vulnerability by sending a steady stream of malicious Secure Sockets Layer (SSL) traffic through the device. An exploit could allow the attacker to cause a DoS condition when the device runs low on system memory. This vulnerability affects Cisco Firepower Threat Defense (FTD) Software Releases 6.0.1 and later, running on any of the following Cisco products: Adaptive Security Appliance (ASA) 5500-X Series Next-Generation Firewalls, Firepower 2100 Series Security Appliances, Firepower 4100 Series Security Appliances, Firepower 9300 Series Security Appliances. Cisco Bug IDs: CSCve02069.

A vulnerability in the TCP normalizer of Cisco Adaptive Security Appliance (ASA) Software (8.0 through 8.7 and 9.0 through 9.6) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause Cisco ASA and FTD to drop any further incoming traffic on all interfaces, resulting in a denial of service (DoS) condition. The vulnerability is due to improper limitation of the global out-of-order TCP queue for specific block sizes. An attacker could exploit this vulnerability by sending a large number of unique permitted TCP connections with out-of-order segments. An exploit could allow the attacker to exhaust available blocks in the global out-of-order TCP queue, causing the dropping of any further incoming traffic on all interfaces and resulting in a DoS condition. Cisco Bug IDs: CSCvb46321.

A vulnerability in the Layer 2 Tunneling Protocol (L2TP) parsing function of Cisco IOS (12.0 through 12.4 and 15.0 through 15.6) and Cisco IOS XE (3.1 through 3.18) could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to insufficient validation of L2TP packets. An attacker could exploit this vulnerability by sending a crafted L2TP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS or Cisco IOS XE Software if the L2TP feature is enabled for the device and the device is configured as an L2TP Version 2 (L2TPv2) or L2TP Version 3 (L2TPv3) endpoint. By default, the L2TP feature is not enabled. Cisco Bug IDs: CSCuy82078.

A vulnerability in the web user interface of Cisco IOS XE 3.1 through 3.17 could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to insufficient resource handling by the affected software when the web user interface is under a high load. An attacker could exploit this vulnerability by sending a high number of requests to the web user interface of the affected software. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. To exploit this vulnerability, the attacker must have access to the management interface of the affected software, which is typically connected to a restricted management network. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS XE Software, if the web user interface of the software is enabled. By default, the web user interface is not enabled. Cisco Bug IDs: CSCup70353.

A memory leak vulnerability exists in Cisco IOS before 15.2(1)T due to a memory leak in the HTTP PROXY Server process (aka CSCtu52820), when configured with Cisco ISR Web Security with Cisco ScanSafe and User Authenticaiton NTLM configured.

A vulnerability in the TCP state machine of Cisco RF Gateway 1 devices could allow an unauthenticated, remote attacker to prevent an affected device from delivering switched digital video (SDV) or video on demand (VoD) streams, resulting in a denial of service (DoS) condition. The vulnerability is due to a processing error with TCP connections to the affected device. An attacker could exploit this vulnerability by establishing a large number of TCP connections to an affected device and not actively closing those TCP connections. A successful exploit could allow the attacker to prevent the affected device from delivering SDV or VoD streams to set-top boxes. Cisco Bug IDs: CSCvf19887.

A vulnerability in Cisco WebEx Meetings Server could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to insufficient limitations on the number of connections that can be made to the affected software. An attacker could exploit this vulnerability by opening multiple connections to the server and exhausting server resources. A successful exploit could cause the server to reload, resulting in a DoS condition. Cisco Bug IDs: CSCvf41006.

A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper handling of HTTPS requests. An attacker could exploit this vulnerability by sending crafted HTTPS requests to an affected system. A successful exploit could allow the attacker to cause resource exhaustion, resulting in a DoS condition.