A vulnerability in the DHCP module 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 the affected device. The vulnerability is due to incorrect processing of certain DHCP packets. An attacker could exploit this vulnerability by sending a crafted DHCP packet to the affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

A vulnerability in Security Group Tag Exchange Protocol (SXP) in Cisco IOS Software, Cisco IOS XE Software, and Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability exists because crafted SXP packets are mishandled. An attacker could exploit this vulnerability by sending specifically crafted SXP packets to the affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.

Multiple vulnerabilities in the Media Gateway Control Protocol (MGCP) inspection feature 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 (DoS) condition on an affected device. The vulnerabilities are due to inefficient memory management. An attacker could exploit these vulnerabilities by sending crafted MGCP packets through an affected device. An exploit could allow the attacker to cause memory exhaustion resulting in a restart of an affected device, causing a DoS condition for traffic traversing the device.

Cisco AsyncOS 8.x before 8.0.8-113, 8.1.x and 8.5.x before 8.5.3-051, 8.6.x and 8.7.x before 8.7.0-171-LD, and 8.8.x before 8.8.0-085 on Web Security Appliance (WSA) devices allows remote attackers to cause a denial of service (memory consumption) via multiple file-range requests, aka Bug ID CSCur39155.

Cisco IOS XE before 2.2.3 on ASR 1000 devices allows remote attackers to cause a denial of service (Embedded Services Processor crash) via a crafted IPv6 packet, aka Bug ID CSCsv98555.

A vulnerability in the Flexible NetFlow Version 9 packet processor of Cisco IOS XE Software for Cisco Catalyst 9800 Series Wireless Controllers could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of parameters in a Flexible NetFlow Version 9 record. An attacker could exploit this vulnerability by sending a malformed Flexible NetFlow Version 9 packet to the Control and Provisioning of Wireless Access Points (CAPWAP) data port of an affected device. An exploit could allow the attacker to trigger an infinite loop, resulting in a process crash that would cause a reload of the device.

Cisco IOS XE before 2.2.3 on ASR 1000 devices allows remote attackers to cause a denial of service (Embedded Services Processor crash) via a crafted IPv4 UDP packet, aka Bug ID CSCsw95482.

Multiple vulnerabilities in the REST API of Cisco UCS Director and Cisco UCS Director Express for Big Data may allow a remote attacker to bypass authentication or conduct directory traversal attacks on an affected device. For more information about these vulnerabilities, see the Details section of this advisory.

Cisco IP Phone 7940 with firmware P0S3-08-7-00 allows remote attackers to cause a denial of service ("486 Busy" responses or device reboot) via a sequence of SIP INVITE transactions in which the Request-URI lacks a user name, a different vulnerability than CVE-2007-4459.

Unspecified vulnerability in Cisco Firewall Services Module (FWSM) 3.2(3) allows remote attackers to cause a denial of service (device reload) via crafted "data in the control-plane path with Layer 7 Application Inspections."

Cisco Unified Communications Manager (CUCM, formerly CallManager) 5.1 before 5.1(2), and Unified CallManager 5.0, allow remote attackers to cause a denial of service (kernel panic) via a flood of SIP INVITE messages to UDP port 5060, which triggers resource exhaustion, aka CSCsi75822.

Cisco Firewall Services Module (FWSM) 3.2(1), and 3.1(5) and earlier, allows remote attackers to cause a denial of service (device reload) via a crafted HTTPS request, aka CSCsi77844.

Memory leak in Cisco Headend System Release allows remote attackers to cause a denial of service (memory consumption) via unspecified vectors, aka Bug ID CSCus91838.

Cisco Content Switching Modules (CSM) 4.2 before 4.2.3a, and Cisco Content Switching Module with SSL (CSM-S) 2.1 before 2.1.2a, allow remote attackers to cause a denial of service (CPU consumption or reboot) via sets of out-of-order TCP packets with unspecified characteristics, aka CSCsd27478.

Cisco Content Switching Modules (CSM) 4.2 before 4.2.7, and Cisco Content Switching Module with SSL (CSM-S) 2.1 before 2.1.6, when service termination is enabled, allow remote attackers to cause a denial of service (reboot) via unspecified vectors related to high network utilization, aka CSCsh57876.

A vulnerability in the Secure/Multipurpose Internet Mail Extensions (S/MIME) Decryption and Verification or S/MIME Public Key Harvesting features of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to cause an affected device to corrupt system memory. A successful exploit could cause the filtering process to unexpectedly reload, resulting in a denial of service (DoS) condition on the device. The vulnerability is due to improper input validation of S/MIME-signed emails. An attacker could exploit this vulnerability by sending a malicious S/MIME-signed email through a targeted device. If Decryption and Verification or Public Key Harvesting is configured, the filtering process could crash due to memory corruption and restart, resulting in a DoS condition. The software could then resume processing the same S/MIME-signed email, causing the filtering process to crash and restart again. A successful exploit could allow the attacker to cause a permanent DoS condition. This vulnerability may require manual intervention to recover the ESA.

The Common Internet File System (CIFS) optimization in Cisco Wide Area Application Services (WAAS) 4.0.7 and 4.0.9, as used by Cisco WAE appliance and the NM-WAE-502 network module, when Edge Services are configured, allows remote attackers to cause a denial of service (loss of service) via a flood of TCP SYN packets to port (1) 139 or (2) 445.

A vulnerability in the internal packet-processing functionality of Cisco Firepower Threat Defense (FTD) Software for Cisco Firepower 2100 Series Security Appliances 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 the affected software improperly validating IP Version 4 (IPv4) and IP Version 6 (IPv6) packets after the software reassembles the packets (following IP Fragmentation). An attacker could exploit this vulnerability by sending a series of malicious, fragmented IPv4 or IPv6 packets to an affected device. A successful exploit could allow the attacker to cause Snort processes on the affected device to hang at 100% CPU utilization, which could cause the device to stop processing traffic and result in a DoS condition until the device is reloaded manually. This vulnerability affects Cisco Firepower Threat Defense (FTD) Software Releases 6.2.1 and 6.2.2, if the software is running on a Cisco Firepower 2100 Series Security Appliance. Cisco Bug IDs: CSCvf91098.

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 a heap overflow condition on the affected device, which will cause the device to reload and result in a DoS condition. Cisco Bug IDs: CSCvg62730.

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 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 crypto engine of the Cisco Integrated Services Module for VPN (ISM-VPN) running Cisco IOS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient handling of VPN traffic by the affected device. An attacker could exploit this vulnerability by sending crafted VPN traffic to an affected device. A successful exploit could allow the attacker to cause the affected device to hang or crash, resulting in a DoS condition. Cisco Bug IDs: CSCvd39267.

A vulnerability in the IPv6 subsystem of Cisco IOS XR Software Release 5.3.4 for the Cisco Aggregation Services Router (ASR) 9000 Series could allow an unauthenticated, remote attacker to trigger a reload of one or more Trident-based line cards, resulting in a denial of service (DoS) condition. The vulnerability is due to incorrect handling of IPv6 packets with a fragment header extension. An attacker could exploit this vulnerability by sending IPv6 packets designed to trigger the issue either to or through the Trident-based line card. A successful exploit could allow the attacker to trigger a reload of Trident-based line cards, resulting in a DoS during the period of time the line card takes to restart. This vulnerability affects Cisco Aggregation Services Router (ASR) 9000 Series when the following conditions are met: The router is running Cisco IOS XR Software Release 5.3.4, and the router has installed Trident-based line cards that have IPv6 configured. A software maintenance upgrade (SMU) has been made available that addresses this vulnerability. The fix has also been incorporated into service pack 7 for Cisco IOS XR Software Release 5.3.4. Cisco Bug IDs: CSCvg46800.

The DHCP relay agent in Cisco Adaptive Security Appliance (ASA) and PIX 7.2 allows remote attackers to cause a denial of service (dropped packets) via a DHCPREQUEST or DHCPINFORM message that causes multiple DHCPACK messages to be sent from DHCP servers to the agent, which consumes the memory allocated for a local buffer. NOTE: this issue only occurs when multiple DHCP servers are used.

A vulnerability in the Session Initiation Protocol (SIP) call-handling functionality of Cisco IP Phone 6800, 7800, and 8800 Series Phones with Multiplatform Firmware could allow an unauthenticated, remote attacker to cause an affected phone to reload unexpectedly, resulting in a temporary denial of service (DoS) condition. The vulnerability exists because the firmware of an affected phone incorrectly handles errors that could occur when an incoming phone call is not answered. An attacker could exploit this vulnerability by sending a set of maliciously crafted SIP packets to an affected phone. A successful exploit could allow the attacker to cause the affected phone to reload unexpectedly, resulting in a temporary DoS condition. This vulnerability affects Cisco IP Phone 6800, 7800, and 8800 Series Phones with Multiplatform Firmware if they are running a Multiplatform Firmware release prior to Release 11.1(2). Cisco Bug IDs: CSCvi24718.

A vulnerability in the SM-1T3/E3 firmware on Cisco Second Generation Integrated Services Routers (ISR G2) and the Cisco 4451-X Integrated Services Router (ISR4451-X) could allow an unauthenticated, remote attacker to cause the ISR G2 Router or the SM-1T3/E3 module on the ISR4451-X to reload, resulting in a denial of service (DoS) condition on an affected device. The vulnerability is due to improper handling of user input. An attacker could exploit this vulnerability by first connecting to the SM-1T3/E3 module console and entering a string sequence. A successful exploit could allow the attacker to cause the ISR G2 Router or the SM-1T3/E3 module on the ISR4451-X to reload, resulting in a DoS condition on an affected device.

A vulnerability in the Cisco Fabric Services component of Cisco FXOS Software and Cisco NX-OS Software 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 insufficiently validates Cisco Fabric Services packets when the software processes packet data. An attacker could exploit this vulnerability by sending a maliciously crafted Cisco Fabric Services packet to an affected device. A successful exploit could allow the attacker to cause a buffer overflow condition on the device, which could cause process crashes and result in a DoS condition on the device. This vulnerability affects Firepower 4100 Series Next-Generation Firewalls, Firepower 9300 Security Appliance, MDS 9000 Series Multilayer Switches, Nexus 2000 Series Fabric Extenders, Nexus 3000 Series Switches, Nexus 3500 Platform Switches, Nexus 5500 Platform Switches, Nexus 5600 Platform Switches, Nexus 6000 Series Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches, Nexus 9000 Series Switches in standalone NX-OS mode, Nexus 9500 R-Series Line Cards and Fabric Modules, UCS 6100 Series Fabric Interconnects, UCS 6200 Series Fabric Interconnects, UCS 6300 Series Fabric Interconnects. Cisco Bug IDs: CSCvd69960, CSCve02463, CSCve04859, CSCve41530, CSCve41537, CSCve41541, CSCve41557.

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 ingress packet processing functionality of the Cisco Virtualized Packet Core-Distributed Instance (VPC-DI) Software could allow an unauthenticated, remote attacker to cause both control function (CF) instances on an affected system to reload, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient handling of user-supplied data by the affected software. An attacker could exploit this vulnerability by sending malicious traffic to the internal distributed instance (DI) network address on an affected system. A successful exploit could allow the attacker to cause an unhandled error condition on the affected system, which would cause the CF instances to reload and consequently cause the entire VPC to reload, resulting in the disconnection of all subscribers and a DoS condition on the affected system. This vulnerability affects Cisco Virtualized Packet Core-Distributed Instance (VPC-DI) Software N4.0 through N5.5 with the Cisco StarOS operating system 19.2 through 21.3. Cisco Bug IDs: CSCve17656.

A vulnerability in the Transport Layer Security (TLS) library 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 the affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by sending a malicious TLS message to an interface enabled for Secure Layer Socket (SSL) services on an affected device. Messages using SSL Version 3 (SSLv3) or SSL Version 2 (SSLv2) cannot be be used to exploit this vulnerability. An exploit could allow the attacker to cause a buffer underflow, triggering a crash on an affected device. This vulnerability affects Cisco ASA Software and Cisco FTD Software that is running on the following Cisco products: Adaptive Security Virtual Appliance (ASAv), Firepower Threat Defense Virtual (FTDv), Firepower 2100 Series Security Appliance. Cisco Bug IDs: CSCve18902, CSCve34335, CSCve38446.

Cisco IOS 12.4 and earlier, when using the crypto packages and SSL support is enabled, allows remote attackers to cause a denial of service via a malformed (1) ClientHello, (2) ChangeCipherSpec, or (3) Finished message during an SSL session.

Unspecified vulnerability in Cisco Adaptive Security Appliance (ASA) and PIX 7.1 before 7.1(2)49 and 7.2 before 7.2(2)17 allows remote attackers to cause a denial of service (device reload) via unknown vectors related to VPN connection termination and password expiry.

A vulnerability in the Bidirectional Forwarding Detection (BFD) offload implementation of Cisco Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches could allow an unauthenticated, remote attacker to cause a crash of the iosd process, causing a denial of service (DoS) condition. The vulnerability is due to insufficient error handling when the BFD header in a BFD packet is incomplete. An attacker could exploit this vulnerability by sending a crafted BFD message to or across an affected switch. A successful exploit could allow the attacker to trigger a reload of the system. This vulnerability affects Catalyst 4500 Supervisor Engine 6-E (K5), Catalyst 4500 Supervisor Engine 6L-E (K10), Catalyst 4500 Supervisor Engine 7-E (K10), Catalyst 4500 Supervisor Engine 7L-E (K10), Catalyst 4500E Supervisor Engine 8-E (K10), Catalyst 4500E Supervisor Engine 8L-E (K10), Catalyst 4500E Supervisor Engine 9-E (K10), Catalyst 4500-X Series Switches (K10), Catalyst 4900M Switch (K5), Catalyst 4948E Ethernet Switch (K5). Cisco Bug IDs: CSCvc40729.

A vulnerability in the IPv6 processing code of Cisco IOS and IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload. The vulnerability is due to incorrect handling of specific IPv6 hop-by-hop options. An attacker could exploit this vulnerability by sending a malicious IPv6 packet to or through the affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition on an affected device.

A vulnerability in the ingress packet processing function of Cisco IOS XR Software for Cisco ASR 9000 Series Aggregation Services Routers 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 allocation when an affected device processes network traffic in software switching mode (punted). An attacker could exploit this vulnerability by sending specific streams of Layer 2 or Layer 3 protocol data units (PDUs) to an affected device. A successful exploit could cause the affected device to run out of buffer resources, which could make the device unable to process or forward traffic, resulting in a DoS condition. The device would need to be restarted to regain functionality.

A vulnerability in the IP Version 4 (IPv4) fragment reassembly function of Cisco 3500, 5500, and 8500 Series Wireless LAN Controller 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 corruption of an internal data structure process that occurs when the affected software reassembles certain IPv4 packets. An attacker could exploit this vulnerability by sending certain malformed IPv4 fragments to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. This vulnerability affects all releases of 8.4 until the first fixed release for the 5500 and 8500 Series Wireless LAN Controllers and releases 8.5.103.0 and 8.5.105.0 for the 3500, 5500, and 8500 Series Wireless LAN Controllers. Cisco Bug IDs: CSCvf89222.

A vulnerability in the Smart Install feature of Cisco IOS Software and Cisco IOS XE 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 validation of packet data. An attacker could exploit this vulnerability by sending a crafted packet to an affected device on TCP port 4786. Only Smart Install client switches are affected. Cisco devices that are configured as a Smart Install director are not affected by this vulnerability. Cisco Bug IDs: CSCvd40673.

A vulnerability in the web framework of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a buffer overflow condition on an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to the affected software improperly parsing malformed HTTP packets that are destined to a device. An attacker could exploit this vulnerability by sending a malformed HTTP packet to an affected device for processing. A successful exploit could allow the attacker to cause a buffer overflow condition on the affected device, resulting in a DoS condition.

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 implementation of Internet Key Exchange Version 1 (IKEv1) functionality in 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 is due to improper validation of specific IKEv1 packets. An attacker could exploit this vulnerability by sending crafted IKEv1 packets to an affected device during an IKE negotiation. A successful exploit could allow the attacker to cause an affected device to reload, resulting in a DoS condition. Cisco Bug IDs: CSCuj73916.