A vulnerability in a legacy capability that allowed for the preloading of VPN clients and plug-ins and that has been available in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to execute arbitrary code with root-level privileges. Administrator-level privileges are required to exploit this vulnerability. This vulnerability is due to improper validation of a file when it is read from system flash memory. An attacker could exploit this vulnerability by copying a crafted file to the disk0: file system of an affected device. A successful exploit could allow the attacker to execute arbitrary code on the affected device after the next reload of the device, which could alter system behavior. Because the injected code could persist across device reboots, Cisco has raised the Security Impact Rating (SIR) of this advisory from Medium to High.

A vulnerability in the management and VPN web servers for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to incomplete error checking when parsing an HTTP header. An attacker could exploit this vulnerability by sending a crafted HTTP request to a targeted web server on a device. A successful exploit could allow the attacker to cause a DoS condition when the device reloads.

A vulnerability in the SAML authentication process of Cisco Secure Client could allow an unauthenticated, remote attacker to conduct a carriage return line feed (CRLF) injection attack against a user. This vulnerability is due to insufficient validation of user-supplied input. An attacker could exploit this vulnerability by persuading a user to click a crafted link while establishing a VPN session. A successful exploit could allow the attacker to execute arbitrary script code in the browser or access sensitive, browser-based information, including a valid SAML token. The attacker could then use the token to establish a remote access VPN session with the privileges of the affected user. Individual hosts and services behind the VPN headend would still need additional credentials for successful access.

A vulnerability in the AnyConnect SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to send packets with another VPN user's source IP address. This vulnerability is due to improper validation of the packet's inner source IP address after decryption. An attacker could exploit this vulnerability by sending crafted packets through the tunnel. A successful exploit could allow the attacker to send a packet impersonating another VPN user's IP address. It is not possible for the attacker to receive return packets.

Multiple vulnerabilities in Cisco Secure Client Software, formerly AnyConnect Secure Mobility Client, could allow an authenticated, local attacker to cause a denial of service (DoS) condition on an affected system. These vulnerabilities are due to an out-of-bounds memory read from Cisco Secure Client Software. An attacker could exploit these vulnerabilities by logging in to an affected device at the same time that another user is accessing Cisco Secure Client on the same system, and then sending crafted packets to a port on that local host. A successful exploit could allow the attacker to crash the VPN Agent service, causing it to be unavailable to all users of the system. To exploit these vulnerabilities, the attacker must have valid credentials on a multi-user system.

Multiple vulnerabilities in Cisco Secure Client Software, formerly AnyConnect Secure Mobility Client, could allow an authenticated, local attacker to cause a denial of service (DoS) condition on an affected system. These vulnerabilities are due to an out-of-bounds memory read from Cisco Secure Client Software. An attacker could exploit these vulnerabilities by logging in to an affected device at the same time that another user is accessing Cisco Secure Client on the same system, and then sending crafted packets to a port on that local host. A successful exploit could allow the attacker to crash the VPN Agent service, causing it to be unavailable to all users of the system. To exploit these vulnerabilities, the attacker must have valid credentials on a multi-user system.

A vulnerability in the implementation of Security Assertion Markup Language (SAML) 2.0 single sign-on (SSO) for remote access VPN in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to intercept the SAML assertion of a user who is authenticating to a remote access VPN session. This vulnerability is due to insufficient validation of the login URL. An attacker could exploit this vulnerability by persuading a user to access a site that is under the control of the attacker, allowing the attacker to modify the login URL. A successful exploit could allow the attacker to intercept a successful SAML assertion and use that assertion to establish a remote access VPN session toward the affected device with the identity and permissions of the hijacked user, resulting in access to the protected network.

A vulnerability in the remote access SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to bypass a configured multiple certificate authentication policy and connect using only a valid username and password. This vulnerability is due to improper error handling during remote access VPN authentication. An attacker could exploit this vulnerability by sending crafted requests during remote access VPN session establishment. A successful exploit could allow the attacker to bypass the configured multiple certificate authentication policy while retaining the privileges and permissions associated with the original connection profile.

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.

A vulnerability in the AnyConnect SSL 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 an implementation error within the SSL/TLS session handling process that can prevent the release of a session handler under specific conditions. An attacker could exploit this vulnerability by sending crafted SSL/TLS traffic to an affected device, increasing the probability of session handler leaks. A successful exploit could allow the attacker to eventually deplete the available session handler pool, preventing new sessions from being established and causing a DoS condition.

A vulnerability in the Multicast Leaf Recycle Elimination (mLRE) feature of Cisco IOS XE Software for Cisco ASR 1000 Series Aggregation Services Routers could allow an unauthenticated, remote attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to incorrect handling of certain IPv6 multicast packets when they are fanned out more than seven times on an affected device. An attacker could exploit this vulnerability by sending a specific IPv6 multicast or IPv6 multicast VPN (MVPNv6) packet through the affected device. A successful exploit could allow the attacker to cause a reload of the affected device, resulting in a DoS condition.

A vulnerability in the Cisco Group Encrypted Transport VPN (GET VPN) feature of Cisco IOS Software and Cisco IOS XE Software could allow an authenticated, remote attacker who has administrative control of either a group member or a key server to execute arbitrary code on an affected device or cause the device to crash. This vulnerability is due to insufficient validation of attributes in the Group Domain of Interpretation (GDOI) and G-IKEv2 protocols of the GET VPN feature. An attacker could exploit this vulnerability by either compromising an installed key server or modifying the configuration of a group member to point to a key server that is controlled by the attacker. A successful exploit could allow the attacker to execute arbitrary code and gain full control of the affected system or cause the affected system to reload, resulting in a denial of service (DoS) condition. For more information, see the Details ["#details"] section of this advisory.

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 conduct a brute force attack in an attempt to identify valid username and password combinations or an authenticated, remote attacker to establish a clientless SSL VPN session with an unauthorized user. This vulnerability is due to improper separation of authentication, authorization, and accounting (AAA) between the remote access VPN feature and the HTTPS management and site-to-site VPN features. An attacker could exploit this vulnerability by specifying a default connection profile/tunnel group while conducting a brute force attack or while establishing a clientless SSL VPN session using valid credentials. A successful exploit could allow the attacker to achieve one or both of the following: Identify valid credentials that could then be used to establish an unauthorized remote access VPN session. Establish a clientless SSL VPN session (only when running Cisco ASA Software Release 9.16 or earlier). Notes: Establishing a client-based remote access VPN tunnel is not possible as these default connection profiles/tunnel groups do not and cannot have an IP address pool configured. This vulnerability does not allow an attacker to bypass authentication. To successfully establish a remote access VPN session, valid credentials are required, including a valid second factor if multi-factor authentication (MFA) is configured. Cisco will release software updates that address this vulnerability. There are workarounds that address this vulnerability.

A vulnerability in the client update process of Cisco AnyConnect Secure Mobility Client Software for Windows and Cisco Secure Client Software for Windows could allow a low-privileged, authenticated, local attacker to elevate privileges to those of SYSTEM. The client update process is executed after a successful VPN connection is established. This vulnerability exists because improper permissions are assigned to a temporary directory that is created during the update process. An attacker could exploit this vulnerability by abusing a specific function of the Windows installer process. A successful exploit could allow the attacker to execute code with SYSTEM privileges.

Multiple vulnerabilities in the web-based management interface of Cisco Small Business RV320 and RV325 Dual Gigabit WAN VPN Routers could allow an authenticated, remote attacker to inject and execute arbitrary commands on the underlying operating system of an affected device. These vulnerabilities are due to insufficient validation of user-supplied input. An attacker could exploit these vulnerabilities by sending malicious input to an affected device. A successful exploit could allow the attacker to execute arbitrary commands as the root user on the underlying Linux operating system of the affected device. To exploit these vulnerabilities, an attacker would need to have valid Administrator credentials on the affected device. Cisco has not released software updates to address these vulnerabilities.

Multiple vulnerabilities in the web-based management interface of Cisco Small Business RV320 and RV325 Dual Gigabit WAN VPN Routers could allow an authenticated, remote attacker to inject and execute arbitrary commands on the underlying operating system of an affected device. These vulnerabilities are due to insufficient validation of user-supplied input. An attacker could exploit these vulnerabilities by sending malicious input to an affected device. A successful exploit could allow the attacker to execute arbitrary commands as the root user on the underlying Linux operating system of the affected device. To exploit these vulnerabilities, an attacker would need to have valid Administrator credentials on the affected device. Cisco has not released software updates to address these vulnerabilities.

A vulnerability in the web-based management interface of Cisco RV340, RV340W, RV345, and RV345P Dual WAN Gigabit VPN Routers could allow an unauthenticated, remote attacker to upload arbitrary files to an affected device. This vulnerability is due to insufficient authorization enforcement mechanisms in the context of file uploads. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. A successful exploit could allow the attacker to upload arbitrary files to the affected device.

A vulnerability in the nginx configurations that are provided as part of the VPN-less reverse proxy for Cisco Finesse could allow an unauthenticated, remote attacker to create a denial of service (DoS) condition for new and existing users who are connected through a load balancer. This vulnerability is due to improper IP address filtering by the reverse proxy. An attacker could exploit this vulnerability by sending a series of unauthenticated requests to the reverse proxy. A successful exploit could allow the attacker to cause all current traffic and subsequent requests to the reverse proxy through a load balancer to be dropped, resulting in a DoS condition.

A vulnerability in the web-based management interface of Cisco Small Business RV160 and RV260 Series VPN Routers could allow an authenticated, remote attacker to execute arbitrary commands on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of user input. An attacker could exploit this vulnerability by sending a crafted request to the web-based management interface of an affected device. A successful exploit could allow the attacker to execute arbitrary commands using root-level privileges on the affected device. To exploit this vulnerability, the attacker must have valid Administrator-level credentials on the affected device.

A vulnerability in the web-based management interface of Cisco Small Business RV340, RV340W, RV345, and RV345P Dual WAN Gigabit VPN Routers could allow an authenticated, remote attacker to execute arbitrary code or cause the web-based management process on the device to restart unexpectedly, resulting in a denial of service (DoS) condition. The attacker must have valid administrator credentials. This vulnerability is due to insufficient validation of user-supplied input to the web-based management interface. An attacker could exploit this vulnerability by sending crafted HTTP input to an affected device. A successful exploit could allow the attacker to execute arbitrary code as the root user on the underlying operating system or cause the web-based management process to restart, resulting in a DoS condition.