| CVE |
Vendors |
Products |
Updated |
CVSS v3.1 |
| A vulnerability in the Remote Access SSL VPN service for Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall 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 insufficient error checking when processing HTTP requests. An attacker could exploit this vulnerability by sending a crafted HTTP request to the Remote Access SSL VPN service on an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. |
| 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. |
| A vulnerability in the per-user-override feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass an access control list (ACL) that is configured for an interface of an affected device. The vulnerability is due to errors that could occur when the affected software constructs and applies per-user-override rules. An attacker could exploit this vulnerability by connecting to a network through an affected device that has a vulnerable configuration. A successful exploit could allow the attacker to access resources that are behind the affected device and would typically be protected by the interface ACL. |
| 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 SSL/TLS client of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to improper memory management when a device initiates SSL/TLS connections. An attacker could exploit this vulnerability by ensuring that the device will connect to an SSL/TLS server that is using specific encryption parameters. A successful exploit could allow the attacker to cause the affected device to unexpectedly reload, resulting in a DoS condition. |
| A vulnerability in the Secure Sockets Layer (SSL) VPN functionality of the Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a reload of the affected system or to remotely execute code. The vulnerability is due to an attempt to double free a region of memory when the webvpn feature is enabled on the Cisco ASA device. An attacker could exploit this vulnerability by sending multiple, crafted XML packets to a webvpn-configured interface on the affected system. An exploit could allow the attacker to execute arbitrary code and obtain full control of the system, or cause a reload of the affected device. This vulnerability affects Cisco ASA Software that is 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, ASA 1000V Cloud Firewall, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4110 Security Appliance, Firepower 9300 ASA Security Module, Firepower Threat Defense Software (FTD). Cisco Bug IDs: CSCvg35618. |
| A vulnerability in the authentication and authorization flows for VPN connections in Cisco Adaptive Security Appliance (ASA) Software and Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to establish a connection as a different user.
This vulnerability is due to a flaw in the authorization verifications during the VPN authentication flow. An attacker could exploit this vulnerability by sending a crafted packet during a VPN authentication. The attacker must have valid credentials to establish a VPN connection. A successful exploit could allow the attacker to establish a VPN connection with access privileges from a different user. |
| A vulnerability in the secure boot implementation of Cisco Secure Firewalls 3100 Series that are running Cisco Adaptive Security Appliance (ASA) Software or Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated attacker with physical access to the device to bypass the secure boot functionality.
This vulnerability is due to a logic error in the boot process. An attacker could exploit this vulnerability by injecting malicious code into a specific memory location during the boot process of an affected device. A successful exploit could allow the attacker to execute persistent code at boot time and break the chain of trust. |
| A vulnerability in dynamic access policies (DAP) functionality 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 improper processing of HostScan data received from the Posture (HostScan) module. An attacker could exploit this vulnerability by sending crafted HostScan data to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition.
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-dap-dos-GhYZBxDU ["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-asa-ftd-dap-dos-GhYZBxDU"]
This advisory is part of the November 2022 release of the Cisco ASA, FTD, and FMC Security Advisory Bundled publication. |
| A vulnerability in the Simple Network Management Protocol (SNMP) feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.
This vulnerability is due to insufficient input validation. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a DoS condition. |
| A vulnerability in the web services of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software, Cisco Secure Firewall Threat Defense (FTD) Software, Cisco IOS Software, Cisco IOS XE Software, and Cisco IOS XR Software could allow an unauthenticated, remote attacker (Cisco ASA and FTD Software) or authenticated, remote attacker (Cisco IOS, IOS XE, and IOS XR Software) with low user privileges to execute arbitrary code on an affected device.
This vulnerability is due to improper validation of user-supplied input in HTTP requests. An attacker could exploit this vulnerability by sending crafted HTTP requests to a targeted web service on an affected device after obtaining additional information about the system, overcoming exploit mitigations, or both. A successful exploit could allow the attacker to execute arbitrary code as root, which may lead to the complete compromise of the affected device.
For more information about this vulnerability, see the Details ["#details"] section of this advisory. |
| A vulnerability in the web interface of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. It is also possible on certain software releases that the ASA will not reload, but an attacker could view sensitive system information without authentication by using directory traversal techniques. The vulnerability is due to lack of proper input validation of the HTTP URL. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. An exploit could allow the attacker to cause a DoS condition or unauthenticated disclosure of information. This vulnerability applies to IPv4 and IPv6 HTTP traffic. This vulnerability affects Cisco ASA Software and Cisco Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 1000V Cloud Firewall, 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: CSCvi16029. |
| Cisco Adaptive Security Appliance (ASA) Software before 8.4(1) on ASA 5500, ASA 5500-X, PIX, and FWSM devices allows local users to gain privileges via invalid CLI commands, aka Bug ID CSCtu74257 or EPICBANANA. |
| Buffer overflow in Cisco Adaptive Security Appliance (ASA) Software through 9.4.2.3 on ASA 5500, ASA 5500-X, ASA Services Module, ASA 1000V, ASAv, Firepower 9300 ASA Security Module, PIX, and FWSM devices allows remote authenticated users to execute arbitrary code via crafted IPv4 SNMP packets, aka Bug ID CSCva92151 or EXTRABACON. |
| 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 VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker to execute arbitrary code on an affected device.
This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests. An attacker with valid VPN user credentials could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to execute arbitrary code as root, possibly resulting in the complete compromise of the affected device. |
| 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 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 Remote Access VPN (RAVPN) service 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) of the RAVPN service.
This vulnerability is due to resource exhaustion. An attacker could exploit this vulnerability by sending a large number of VPN authentication requests to an affected device. A successful exploit could allow the attacker to exhaust resources, resulting in a DoS of the RAVPN service on the affected device. Depending on the impact of the attack, a reload of the device may be required to restore the RAVPN service. Services that are not related to VPN are not affected.
Cisco Talos discussed these attacks in the blog post Large-scale brute-force activity targeting VPNs, SSH services with commonly used login credentials. |
