| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| Update: On November 5, 2025, Cisco became aware of a new attack variant against devices running Cisco Secure ASA Software or Cisco Secure FTD Software releases that are affected by CVE-2025-20333 and CVE-2025-20362. This attack can cause unpatched devices to unexpectedly reload, leading to denial of service (DoS) conditions. Cisco strongly recommends that all customers upgrade to the fixed software releases that are listed in the Fixed Software ["#fs"] section of this advisory.
A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to access restricted URL endpoints that are related to remote access VPN that should otherwise be inaccessible without authentication.
This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web server on a device. A successful exploit could allow the attacker to access a restricted URL without authentication. |
| 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 SIP inspection engine of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a crash and reload of an affected device, resulting in a denial of service (DoS) condition.The vulnerability is due to a crash that occurs during a hash lookup for a SIP pinhole connection. An attacker could exploit this vulnerability by sending crafted SIP traffic through an affected device. A successful exploit could allow the attacker to cause a crash and reload of the affected device. |
| A vulnerability in the software-based SSL/TLS message handler 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, resulting in a denial of service (DoS) condition. This vulnerability is due to insufficient validation of SSL/TLS messages when the device performs software-based SSL/TLS decryption. An attacker could exploit this vulnerability by sending a crafted SSL/TLS message to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: Datagram TLS (DTLS) messages cannot be used to exploit this vulnerability. |
| A vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to send traffic that should be denied through an affected device.
This vulnerability is due to improper error handling when an affected device that is joining a cluster runs out of memory while replicating access control rules. An attacker could exploit this vulnerability by sending traffic that should be blocked through the device. A successful exploit could allow the attacker to bypass access controls and reach devices in protected networks. |
| 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 VPN web services component of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to conduct a cross-site scripting (XSS) attack against a browser that is accessing an affected device.
This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by persuading a user to follow a link to a malicious website that is designed to submit malicious input to the affected application. A successful exploit could allow the attacker to execute arbitrary HTML or script code in the browser in the context of the VPN web server. |
| Multiple vulnerabilities in 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. These vulnerabilities are due to lack of proper input validation of the HTTPS request. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: This vulnerability affects only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section. |
| 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. |
| Multiple vulnerabilities in 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. These vulnerabilities are due to lack of proper input validation of the HTTPS request. An attacker could exploit these vulnerabilities by sending a crafted HTTPS request to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. Note: This vulnerability affects only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section. |
| A vulnerability in the LUA interperter of the Remote Access SSL VPN feature of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker with a valid VPN connection to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This does not affect the management or MUS interfaces.
This vulnerability is due to trusting user input without validation in the LUA interprerter. An attacker could exploit this vulnerability by sending crafted HTTP packets to the Remote Access SSL VPN server. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. |
| 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 retrieve memory contents on an affected device, which could lead to the disclosure of confidential information. The vulnerability is due to a buffer tracking issue when the software parses invalid URLs that are requested from the web services interface. An attacker could exploit this vulnerability by sending a crafted GET request to the web services interface. A successful exploit could allow the attacker to retrieve memory contents, which could lead to the disclosure of confidential information. Note: This vulnerability affects only specific AnyConnect and WebVPN configurations. For more information, see the Vulnerable Products section. |
| A vulnerability in the SSL VPN feature for Cisco Adaptive Security Appliance (ASA) Software and Cisco 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.
This vulnerability is due to a logic error in memory management when the device is handling SSL VPN connections. An attacker could exploit this vulnerability by sending crafted SSL/TLS packets to the SSL VPN server of the affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. |
| A vulnerability in the OSPF protocol of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition. If OSPF authentication is enabled, the attacker must know the secret key to exploit this vulnerability.
This vulnerability is due to insufficient input validation when processing OSPF update packets. An attacker could exploit this vulnerability by sending crafted OSPF update packets. A successful exploit could allow the attacker to create a buffer overflow, causing the affected device to reload, resulting in a DoS condition. |
| A vulnerability in the Dynamic Access Policies (DAP) feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to cause an affected device to reload unexpectedly. To exploit this vulnerability, an attacker would need valid remote access VPN user credentials on the affected device.
This vulnerability is due to improper validation of data in HTTPS POST requests. An attacker could exploit this vulnerability by sending a crafted HTTPS POST request to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a denial of service (DoS) condition. |
| A vulnerability in the Internet Key Exchange Version 2 Mobility and Multihoming Protocol (MOBIKE) feature for the Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a memory leak or a reload of an affected device that leads to a denial of service (DoS) condition. The vulnerability is due to the incorrect processing of certain MOBIKE packets. An attacker could exploit this vulnerability by sending crafted MOBIKE packets to an affected device to be processed. A successful exploit could cause an affected device to continuously consume memory and eventually reload, resulting in a DoS condition. The MOBIKE feature is supported only for IPv4 addresses. |
| 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. |
| A vulnerability in the TLS cryptography functionality of 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 improper data validation during the TLS 1.3 handshake. An attacker could exploit this vulnerability by sending a crafted TLS 1.3 packet to an affected system through a TLS 1.3-enabled listening socket. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.
Note: This vulnerability can also impact the integrity of a device by causing VPN HostScan communication failures or file transfer failures when Cisco ASA Software is upgraded using Cisco Adaptive Security Device Manager (ASDM). |
| Multiple vulnerabilities in the Application Layer Protocol Inspection 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 vulnerabilities are due to logical errors during traffic inspection. An attacker could exploit these vulnerabilities by sending a high volume of malicious traffic across an affected device. An exploit could allow the attacker to cause a deadlock condition, resulting in a reload of an affected device. These vulnerabilities affect Cisco ASA Software and Cisco FTD Software configured for Application Layer Protocol Inspection running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4100 Series Security Appliance, Firepower 9300 ASA Security Module, FTD Virtual (FTDv). Cisco Bug IDs: CSCve61540, CSCvh23085, CSCvh95456. |
| 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. |
