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 Open Shortest Path First (OSPF) implementation in 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. The vulnerability is due to incorrect processing of certain OSPF packets. An attacker could exploit this vulnerability by sending a series of crafted OSPF packets to be processed by an affected device. A successful exploit could allow the attacker to continuously consume memory on an affected device and eventually cause it to reload, resulting in a denial of service (DoS) condition.

A vulnerability in DNS over IPv6 packet processing for Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to unexpectedly reload, resulting in a denial of service (DoS) condition. The vulnerability is due to improper length validation of a field in an IPv6 DNS packet. An attacker could exploit this vulnerability by sending a crafted DNS query over IPv6, which traverses the affected device. An exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. This vulnerability is specific to DNS over IPv6 traffic only.

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 how Cisco Firepower Threat Defense (FTD) Software handles session timeouts for management connections could allow an unauthenticated, remote attacker to cause a buildup of remote management connections to an affected device, which could result in a denial of service (DoS) condition. The vulnerability exists because the default session timeout period for specific to-the-box remote management connections is too long. An attacker could exploit this vulnerability by sending a large and sustained number of crafted remote management connections to an affected device, resulting in a buildup of those connections over time. A successful exploit could allow the attacker to cause the remote management interface or Cisco Firepower Device Manager (FDM) to stop responding and cause other management functions to go offline, resulting in a DoS condition. The user traffic that is flowing through the device would not be affected, and the DoS condition would be isolated to remote management only.

A vulnerability in the web services interface of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct directory traversal attacks and obtain read and delete access to sensitive files on a targeted system. The vulnerability is due to a lack of proper input validation of the HTTP URL. An attacker could exploit this vulnerability by sending a crafted HTTP request containing directory traversal character sequences. An exploit could allow the attacker to view or delete arbitrary files on the targeted system. When the device is reloaded after exploitation of this vulnerability, any files that were deleted are restored. The attacker can only view and delete files within the web services file system. This file system is enabled when the affected device is configured with either WebVPN or AnyConnect features. This vulnerability can not be used to obtain access to ASA or FTD system files or underlying operating system (OS) files. Reloading the affected device will restore all files within the web services file system.

A vulnerability in the management access list configuration of Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass a configured management interface access list on an affected system. The vulnerability is due to the configuration of different management access lists, with ports allowed in one access list and denied in another. An attacker could exploit this vulnerability by sending crafted remote management traffic to the local IP address of an affected system. A successful exploit could allow the attacker to bypass the configured management access list policies, and traffic to the management interface would not be properly denied.

A vulnerability in the generic routing encapsulation (GRE) tunnel decapsulation feature 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 a memory handling error when GRE over IPv6 traffic is processed. An attacker could exploit this vulnerability by sending crafted GRE over IPv6 packets with either IPv4 or IPv6 payload through an affected device. A successful exploit could allow the attacker to cause the device to crash, resulting in a DoS condition.

A vulnerability in the Kerberos authentication feature of Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to impersonate the Kerberos key distribution center (KDC) and bypass authentication on an affected device that is configured to perform Kerberos authentication for VPN or local device access. The vulnerability is due to insufficient identity verification of the KDC when a successful authentication response is received. An attacker could exploit this vulnerability by spoofing the KDC server response to the ASA device. This malicious response would not have been authenticated by the KDC. A successful attack could allow an attacker to bypass Kerberos authentication.

A vulnerability in the Cisco ASA that could allow a remote attacker to successfully authenticate using the Cisco AnyConnect VPN client if the Secondary Authentication type is LDAP and the password is left blank, providing the primary credentials are correct. The vulnerabilities is due to improper input validation of certain parameters passed to the affected software. An attacker must have the correct primary credentials in order to successfully exploit this vulnerability.

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 the WebVPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause increased CPU utilization on an affected device. The vulnerability is due to excessive processing load for a specific WebVPN HTTP page request. An attacker could exploit this vulnerability by sending multiple WebVPN HTTP page load requests for a specific URL. A successful exploit could allow the attacker to increase CPU load on the device, resulting in a denial of service (DoS) condition, which could cause traffic to be delayed through the device.

A vulnerability in the Clientless SSL VPN (WebVPN) portal of Cisco Adaptive Security Appliance (ASA) and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the web-based management interface of an affected device. The vulnerability is due to insufficient validation of user-supplied input by the web-based management interface of an affected device. An attacker could exploit this vulnerability by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the interface or allow the attacker to access sensitive browser-based information.

A vulnerability in the Secure Copy (SCP) feature of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerability is due to the use of an incorrect data type for a length variable. An attacker could exploit this vulnerability by initiating the transfer of a large file to an affected device via SCP. To exploit this vulnerability, the attacker would need to have valid privilege level 15 credentials on the affected device. A successful exploit could allow the attacker to cause the length variable to roll over, which could cause the affected device to crash.

A vulnerability in the Session Initiation Protocol (SIP) inspection 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 an affected device. The vulnerability is due to improper parsing of SIP messages. An attacker could exploit this vulnerability by sending a malicious SIP packet through an affected device. A successful exploit could allow the attacker to trigger an integer underflow, causing the software to try to read unmapped memory and resulting in a crash.

A vulnerability in the Secure Sockets Layer (SSL) VPN feature of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition that prevents the creation of new SSL/Transport Layer Security (TLS) connections to an affected device. The vulnerability is due to incorrect handling of Base64-encoded strings. An attacker could exploit this vulnerability by opening many SSL VPN sessions to an affected device. The attacker would need to have valid user credentials on the affected device to exploit this vulnerability. A successful exploit could allow the attacker to overwrite a special system memory location, which will eventually result in memory allocation errors for new SSL/TLS sessions to the device, preventing successful establishment of these sessions. A reload of the device is required to recover from this condition. Established SSL/TLS connections to the device and SSL/TLS connections through the device are not affected. Note: Although this vulnerability is in the SSL VPN feature, successful exploitation of this vulnerability would affect all new SSL/TLS sessions to the device, including management sessions.

A vulnerability in the Open Shortest Path First (OSPF) implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software improperly parses certain options in OSPF link-state advertisement (LSA) type 11 packets. An attacker could exploit this vulnerability by sending a crafted LSA type 11 OSPF packet to an affected device. A successful exploit could allow the attacker to cause a reload of the affected device, resulting in a DoS condition for client traffic that is traversing the device.

A vulnerability in the FTP inspection engine of Cisco Adaptive Security (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. The vulnerability is due to insufficient validation of FTP data. An attacker could exploit this vulnerability by sending malicious FTP traffic through an affected device. A successful exploit could allow the attacker to cause a DoS condition on the affected device.

A vulnerability in the web-based management interface of Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to conduct a cross-site request forgery (CSRF) attack on an affected system. The vulnerability is due to insufficient CSRF protections for the web-based management interface on an affected device. An attacker could exploit this vulnerability by persuading a user of the interface to follow a malicious link. A successful exploit could allow the attacker to perform arbitrary actions with the privilege level of the affected user. If the user has administrative privileges, the attacker could alter the configuration of, extract information from, or reload an affected device.

Multiple vulnerabilities in the WebVPN service of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a user of the WebVPN portal of an affected device. The vulnerabilities exist because the software insufficiently validates user-supplied input on an affected device. An attacker could exploit these vulnerabilities by persuading a user of the interface to click a crafted link. A successful exploit could allow the attacker to execute arbitrary script code in the context of the affected interface or access sensitive browser-based information. An attacker would need administrator privileges on the device to exploit these vulnerabilities.