Cisco Prime Network Analysis Module (NAM) before 6.2(1-b) miscalculates IPv6 payload lengths, which allows remote attackers to cause a denial of service (mond process crash and monitoring outage) via crafted IPv6 packets, aka Bug ID CSCuy37324.

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.

Memory leak in the gk_circuit_info_do_in_acf function in the H.323 implementation in Cisco IOS before 15.0(1)XA allows remote attackers to cause a denial of service (memory consumption) via a large number of calls over a long duration, as demonstrated by InterZone Clear Token (IZCT) test traffic, aka Bug ID CSCsz72535.

Cisco Adaptive Security Appliances (ASA) 5500 series devices with software before 8.2(3) allow remote attackers to cause a denial of service (ASDM syslog outage) via a long URL, aka Bug IDs CSCsm11264 and CSCtb92911.

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.

A vulnerability in the software cryptography module of the Cisco Adaptive Security Virtual Appliance (ASAv) and Firepower 2100 Series running Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause an unexpected reload of the device that results in a denial of service (DoS) condition. The vulnerability is due to a logic error with how the software cryptography module handles IPsec sessions. An attacker could exploit this vulnerability by creating and sending traffic in a high number of IPsec sessions through the targeted device. A successful exploit could cause the device to reload and result in a DoS condition.

The proxy process on Cisco Web Security Appliance (WSA) devices through 9.1.0-070 allows remote attackers to cause a denial of service (CPU consumption) by establishing an FTP session and then improperly terminating the control connection after a file transfer, aka Bug ID CSCuy43468.

libclamav in ClamAV (aka Clam AntiVirus), as used in Advanced Malware Protection (AMP) on Cisco Email Security Appliance (ESA) devices before 9.7.0-125 and Web Security Appliance (WSA) devices before 9.0.1-135 and 9.1.x before 9.1.1-041, allows remote attackers to cause a denial of service (AMP process restart) via a crafted document, aka Bug IDs CSCuv78533 and CSCuw60503.

A vulnerability in Google-defined remote procedure call (gRPC) handling in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause the Event Management Service daemon (emsd) to crash due to a system memory leak, resulting in a denial of service (DoS) condition. This vulnerability affects Cisco IOS XR Software with gRPC enabled. More Information: CSCvb14433. Known Affected Releases: 6.1.1.BASE 6.2.1.BASE. Known Fixed Releases: 6.2.1.22i.MGBL 6.1.22.9i.MGBL 6.1.21.12i.MGBL 6.1.2.13i.MGBL.

The TCP implementation in Cisco Videoscape Distribution Suite for Internet Streaming (VDS-IS) 3.3(0), 3.3(1), 4.0(0), and 4.1(0) does not properly initiate new TCP sessions when a previous session is in a FIN wait state, which allows remote attackers to cause a denial of service (TCP outage) via vectors involving FIN packets, aka Bug ID CSCuy45136.

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 TelePresence Video Communications Server (VCS) X8.x before X8.7.2 allows remote attackers to cause a denial of service (service disruption) via a crafted URI in a SIP header, aka Bug ID CSCuy43258.

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.

Cisco IOS XR 4.2.3, 4.3.0, 4.3.4, and 5.3.1 on ASR 9000 devices allows remote attackers to cause a denial of service (CRC and symbol errors, and interface flap) via crafted bit patterns in packets, aka Bug ID CSCuv78548.

The packet-processing microcode in Cisco IOS 15.2(2)EA, 15.2(2)EA1, 15.2(2)EA2, and 15.2(4)EA on Industrial Ethernet 4000 devices and 15.2(2)EB and 15.2(2)EB1 on Industrial Ethernet 5000 devices allows remote attackers to cause a denial of service (packet data corruption) via crafted IPv4 ICMP packets, aka Bug ID CSCuy13431.

A vulnerability in the detection engine of Cisco Firepower Threat Defense Software could allow an unauthenticated, remote attacker to cause the unexpected restart of the SNORT detection engine, resulting in a denial of service (DoS) condition. The vulnerability is due to the incomplete error handling of the SSL or TLS packet header during the connection establishment. An attacker could exploit this vulnerability by sending a crafted SSL or TLS packet during the connection handshake. An exploit could allow the attacker to cause the SNORT detection engine to unexpectedly restart, resulting in a partial DoS condition while the detection engine restarts. Versions prior to 6.2.3.4 are affected.

A vulnerability in the Local Packet Transport Services (LPTS) ingress frame-processing functionality of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause one of the LPTS processes on an affected system to restart unexpectedly, resulting in a brief denial of service (DoS) condition. The vulnerability is due to incomplete LPTS frame validation by the affected software. An attacker could exploit this vulnerability by sending crafted XML requests to the management interface of an affected system. A successful exploit could allow the attacker to cause one of the LPTS processes on the affected system to restart unexpectedly, which would impact LPTS traffic and cause a brief DoS condition while the process restarts. Cisco Bug IDs: CSCvf76332.

The web-management GUI implementation on Cisco Small Business SG300 devices 1.4.1.x allows remote attackers to cause a denial of service (HTTPS outage) via crafted HTTPS requests, aka Bug ID CSCuw87174.

A vulnerability in the Zone-Based Firewall code of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a device to reload. The vulnerability is due to the way fragmented packets are handled in the firewall code. An attacker could exploit this vulnerability by sending fragmented IP Version 4 or IP Version 6 packets through an affected device. An exploit could allow the attacker to cause the device to crash, resulting in a denial of service (DoS) condition. The following releases of Cisco IOS XE Software are vulnerable: Everest-16.4.1, Everest-16.4.2, Everest-16.5.1, Everest-16.5.1b, Everest-16.6.1, Everest-16.6.1a. Cisco Bug IDs: CSCvf60296.

A vulnerability in the Session Initiation Protocol (SIP) call processing of Cisco Meeting Server (CMS) software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition of the Cisco Meeting Server. The vulnerability is due to insufficient validation of Session Description Protocol (SDP) messages. An attacker could exploit this vulnerability by sending a crafted SDP message to the CMS call bridge. An exploit could allow the attacker to cause the CMS to reload, causing a DoS condition for all connected clients. Versions prior to 2.3.9 are affected.

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 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.

The Active Directory (AD) integration component in Cisco Identity Service Engine (ISE) before 1.2.0.899 patch 7, when AD group-membership authorization is enabled, allows remote attackers to cause a denial of service (authentication outage) via a crafted Password Authentication Protocol (PAP) authentication request, aka Bug ID CSCun25815.

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.

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.

A vulnerability in the data acquisition (DAQ) component of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass configured access control policies or cause a denial of service (DoS) condition. The vulnerability exists because the affected software improperly manages system memory resources when inspecting traffic. An attacker could exploit this vulnerability by generating specific traffic patterns for the software to inspect. A successful exploit could allow the attacker to exhaust system memory resources used for traffic inspection. Depending on the configuration, the FTD Software could fail open and cease to inspect traffic or fail closed and result in a DoS condition. This vulnerability may require manual intervention to restore the software.

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 implementation of the Border Gateway Protocol (BGP) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to incorrect processing of a BGP update message that contains a specific BGP attribute. An attacker could exploit this vulnerability by sending BGP update messages that include a specific, malformed attribute to be processed by an affected system. A successful exploit could allow the attacker to cause the BGP process to restart unexpectedly, resulting in a DoS condition. The Cisco implementation of BGP accepts incoming BGP traffic only from explicitly defined peers. To exploit this vulnerability, the malicious BGP update message would need to come from a configured, valid BGP peer or would need to be injected by the attacker into the victim’s BGP network on an existing, valid TCP connection to a BGP peer.

A vulnerability in the system resource management of Cisco Elastic Services Controller (ESC) could allow an unauthenticated, remote attacker to cause a denial of service (DoS) to the health monitor API on an affected device. The vulnerability is due to inadequate provisioning of kernel parameters for the maximum number of TCP connections and SYN backlog. 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 block TCP listening ports that are used by the health monitor API. This vulnerability only affects customers who use the health monitor API.

A vulnerability in the VXLAN Operation, Administration, and Maintenance (OAM) feature of Cisco NX-OS Software, known as NGOAM, 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 specific packets with a Transparent Interconnection of Lots of Links (TRILL) OAM EtherType. An attacker could exploit this vulnerability by sending crafted packets, including the TRILL OAM EtherType of 0x8902, to a device that is part of a VXLAN Ethernet VPN (EVPN) fabric. A successful exploit could allow the attacker to cause an affected device to experience high CPU usage and consume excessive system resources, which may result in overall control plane instability and cause the affected device to reload. Note: The NGOAM feature is disabled by default.

Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute denial of service (DoS) attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

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 (1) malformed or (2) large ISAKMP packets.

A vulnerability in the software-based SSL/TLS message handler of 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 vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL decryption. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message through an affected device. SSL/TLS messages sent to an affected device do not trigger this vulnerability. A successful exploit could allow the attacker to cause a process to crash. This crash would then trigger a reload of the device. No manual intervention is needed to recover the device after the reload.

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 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).

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.

A vulnerability in the web UI of Cisco Umbrella could allow an unauthenticated, remote attacker to negatively affect the performance of this service. The vulnerability exists due to insufficient rate limiting controls in the web UI. An attacker could exploit this vulnerability by sending crafted HTTPS packets at a high and sustained rate. A successful exploit could allow the attacker to negatively affect the performance of the web UI. Cisco has addressed this vulnerability.

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 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.

A vulnerability in the email parsing module in Clam AntiVirus (ClamAV) Software version 0.103.1 and all prior versions could allow an unauthenticated, remote attacker to cause a denial of service condition on an affected device. The vulnerability is due to improper variable initialization that may result in an NULL pointer read. An attacker could exploit this vulnerability by sending a crafted email to an affected device. An exploit could allow the attacker to cause the ClamAV scanning process crash, resulting in a denial of service condition.

Multiple vulnerabilities in Cisco SD-WAN products could allow an unauthenticated, remote attacker to execute denial of service (DoS) attacks against an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

Cisco Virtual Private Network (VPN) Client 3.5.4 and earlier allows remote attackers to cause a denial of service (CPU consumption) via a packet with a zero-length payload.

A vulnerability in the SSH service of the Cisco StarOS operating system could allow an unauthenticated, remote attacker to cause an affected device to stop processing traffic, resulting in a denial of service (DoS) condition. The vulnerability is due to a logic error that may occur under specific traffic conditions. An attacker could exploit this vulnerability by sending a series of crafted packets to an affected device. A successful exploit could allow the attacker to prevent the targeted service from receiving any traffic, which would lead to a DoS condition on the affected device.

Multiple vulnerabilities in Cisco SD-WAN vEdge Software could allow an attacker to execute arbitrary code as the root user or cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

A vulnerability in the Internet Key Exchange version 1 (IKEv1) 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 vulnerability is due to improper management of system memory. An attacker could exploit this vulnerability by sending malicious IKEv1 traffic to an affected device. The attacker does not need valid credentials to authenticate the VPN session, nor does the attacker's source address need to match a peer statement in the crypto map applied to the ingress interface of the affected device. An exploit could allow the attacker to exhaust system memory resources, leading to a reload of an affected device.

A vulnerability in Ethernet over GRE (EoGRE) packet processing of Cisco IOS XE Wireless Controller Software for the Cisco Catalyst 9800 Family Wireless Controller, Embedded Wireless Controller, and Embedded Wireless on Catalyst 9000 Series Switches could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper processing of malformed EoGRE packets. An attacker could exploit this vulnerability by sending malicious packets to the affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Multiple vulnerabilities in the ingress packet processing function of Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

A vulnerability in the network stack 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 exists because the software improperly releases resources when it processes certain IPv6 packets that are destined to an affected device. An attacker could exploit this vulnerability by sending multiple crafted IPv6 packets to an affected device. A successful exploit could cause the network stack to run out of available buffers, impairing operations of control plane and management plane protocols and resulting in a DoS condition. Manual intervention would be required to restore normal operations on the affected device. For more information about the impact of this vulnerability, see the Details section of this advisory.