Cisco Adaptive Security Appliance

OSPF LSU Heap Corruption DoS in Cisco Secure Firewall ASA/FTD
CVE-2026-20025 6.8 - Medium - March 04, 2026

A vulnerability in the OSPF protocol of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an authenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition. To exploit this vulnerability, the attacker must have the OSPF secret key. This vulnerability is due to insufficient input validation when processing OSPF link-state update (LSU) packets. An attacker could exploit this vulnerability by sending crafted OSPF LSU packets. A successful exploit could allow the attacker to corrupt the heap, causing the device to reload, resulting in a DoS condition.

Integer Overflow or Wraparound

Cisco Secure Firewall ASA/FTD OSPF DoS via Auth Attack
CVE-2026-20024 6.8 - Medium - March 04, 2026

A vulnerability in the OSPF protocol of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an authenticated, adjacent attacker to cause an affected device to reload unexpectedly, resulting in a DoS condition. To exploit this vulnerability, the attacker must have the OSPF secret key. This vulnerability is due to heap corruption in OSPF when parsing packets. An attacker could exploit this vulnerability by sending crafted packets to the OSPF service. A successful exploit could allow the attacker to corrupt the heap, causing the affected device to reload, resulting in a DoS condition.

Buffer Overflow

Cisco ASA/FTD OSPF Memory Corruption Causing DoS
CVE-2026-20023 6.1 - Medium - March 04, 2026

A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, adjacent attacker to corrupt memory on an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to memory corruption when parsing OSPF protocol packets. An attacker could exploit this vulnerability by sending crafted OSPF packets to an affected device. A successful exploit could allow the attacker to cause memory corruption causing the affected device to reboot, resulting in a DoS condition.

Memory Corruption

DoS via OSPF LSU Overflow in Cisco Secure Firewall ASA/FTD
CVE-2026-20022 6.1 - Medium - March 04, 2026

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 when OSPF canonicalization debug is enabled by using the command debug ip ospf canon. This vulnerability is due to insufficient input validation when processing OSPF LSU packets. An attacker could exploit this vulnerability by sending crafted unauthenticated OSPF packets. A successful exploit could allow the attacker to write to memory outside of the packet data, causing the device to reload, resulting in a DoS condition.

Untrusted pointer offset

OSPF Authenticated Adjacent DoS via Memory Exhaustion in Cisco ASA/FTD
CVE-2026-20021 4.3 - Medium - March 04, 2026

A vulnerability in the OSPF protocol of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, adjacent attacker to exhaust memory on an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to improperly validating input by the OSPF protocol when parsing packets. An attacker could exploit this vulnerability by by sending crafted OSPF packets to an affected device. A successful exploit could allow the attacker to exhaust memory on the affected device, resulting in a DoS condition.

Memory Leak

Cisco Secure Firewall ASA/FTD OSPF DoS via Buffer Overflow
CVE-2026-20020 6.8 - Medium - March 04, 2026

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.

Improper Input Validation

Cisco ASA/FTD: Cluster Replication RMEM Bypass (CVE-2026-20073)
CVE-2026-20073 5.8 - Medium - March 04, 2026

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.

Authorization

Cisco Secure Firewall ASA/FTD XSS via Unvalidated SAML 2.0 SSO
CVE-2026-20102 6.1 - Medium - March 04, 2026

A vulnerability in the SAML 2.0 single sign-on (SSO) feature of Cisco Secure Firewall 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 the SAML feature and access sensitive, browser-based information. This vulnerability is due to insufficient input validation of multiple HTTP parameters. An attacker could exploit this vulnerability by persuading a user to access a malicious link. A successful exploit could allow the attacker to conduct a reflected XSS attack through an affected device.

XSS

VPN Web Services XSS in Cisco Secure Firewall ASA/FTD
CVE-2026-20070 6.1 - Medium - March 04, 2026

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.

Basic XSS

VPN Webservices XSS in Cisco Secure Firewall ASA/FTD Remote Attack
CVE-2026-20069 4.3 - Medium - March 04, 2026

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 browser-based attacks against users of an affected device. This vulnerability is due to improper validation of HTTP requests. An attacker could exploit this vulnerability by persuading a user to visit a website that is designed to pass malicious HTTP requests to a device that is running Cisco Secure Firewall ASA Software or Cisco Secure FTD Software and has web services endpoints supporting VPN features enabled. A successful exploit could allow the attacker to reflect malicious input from the affected device to the browser that is in use and conduct browser-based attacks, including cross-site scripting (XSS) attacks. The attacker is not able to directly impact the affected device.

HTTP Request Smuggling

Cisco ASA TCP SYN Flood DoS via Mismanaged Connection Limits
CVE-2026-20082 8.6 - High - March 04, 2026

A vulnerability in the handling of the embryonic connection limits in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause incoming TCP SYN packets to be dropped incorrectly. This vulnerability is due to improper handling of new, incoming TCP connections that are destined to management or data interfaces when the device is under a TCP SYN flood attack. An attacker could exploit this vulnerability by sending a crafted stream of traffic to an affected device. A successful exploit could allow the attacker to prevent all incoming TCP connections to the device from being established, including remote management access, Remote Access VPN (RAVPN) connections, and all network protocols that are TCP-based. This results in a denial of service (DoS) condition for affected features.

Missing Release of Resource after Effective Lifetime

Auth Bypass CLI ASA SCP Context File Copy
CVE-2026-20062 7.2 - High - March 04, 2026

A vulnerability in the CLI of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software in multiple context mode could allow an authenticated, local attacker with administrative privileges in one context to copy files to or from another context, including configuration files. This vulnerability is due to improper access controls for Secure Copy Protocol (SCP) operations when the CiscoSSH stack is enabled. An attacker could exploit this vulnerability by authenticating to a non-admin context of the device and issuing crafted SCP copy commands in that non-admin context. A successful exploit could allow the attacker to read, create, or overwrite sensitive files that belong to another context, including the admin and system contexts. The attacker cannot directly impact the availability of services pertaining to other contexts. To exploit this vulnerability, the attacker must have valid administrative credentials for a non-admin context. Note: An attacker cannot list or enumerate files from another context and would need to know the exact file path, which increases the complexity of a successful attack.

Incorrect Execution-Assigned Permissions

Cisco ASA/FTD GCM-IKEv2 Memory Overrun Causing DoS
CVE-2026-20049 7.7 - High - March 04, 2026

A vulnerability in the processing of Galois/Counter Mode (GCM)-encrypted Internet Key Exchange version 2 (IKEv2) IPsec traffic of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall 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 the allocation of an insufficiently sized block of memory. An attacker could exploit this vulnerability by sending crafted GCM-encrypted IPsec traffic to an affected device. A successful exploit could allow the attacker to cause an unexpected reload of the device, resulting in a DoS condition. To exploit this vulnerability, the attacker must have valid credentials to establish a VPN connection with the affected device.

Incorrect Calculation of Buffer Size

Cisco ASA/FTD IKEv2 DoS via Memory Leak
CVE-2026-20015 5.8 - Medium - March 04, 2026

A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device that may impact the availability of services to devices elsewhere in the network. This vulnerability is due to a memory leak when parsing IKEv2 packets. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit could allow the attacker to exhaust resources, causing a DoS condition that will eventually require the device to be manually reloaded.

Memory Leak

Cisco ASA/FTD IKEv2 Authenticated DoS via Crafted Packets
CVE-2026-20014 7.7 - High - March 04, 2026

A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an authenticated, remote attacker with valid VPN user credentials to cause a DoS condition on an affected device that may also impact the availability of services to devices elsewhere in the network. This vulnerability is due to the improper processing of IKEv2 packets. An attacker could exploit this vulnerability by sending crafted, authenticated IKEv2 packets to an affected device. A successful exploit could allow the attacker to exhaust memory, causing the device to reload.

Memory Leak

Cisco Secure Firewall ASA/FTD IKEv2 DoS
CVE-2026-20013 5.8 - Medium - March 04, 2026

A vulnerability in the IKEv2 feature of Cisco Secure Firewall ASA Software and Cisco Secure FTD Software could allow an unauthenticated, remote attacker to cause a DoS condition on an affected device that may also impact the availability of services to devices elsewhere in the network. This vulnerability is due to memory exhaustion caused by not freeing memory during IKEv2 packet processing. An attacker could exploit this vulnerability by sending crafted IKEv2 packets to an affected device. A successful exploit could allow the attacker to exhaust resources, causing a DoS condition that will eventually require the device to manually reload.

Memory Leak

Cisco ASA/FTD Mem Exhaustion DoS via SSL VPN
CVE-2026-20106 5.3 - Medium - March 04, 2026

A vulnerability in the Remote Access SSL VPN, HTTP management and MUS functionality, of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to exhaust device memory resulting in a denial of service (DoS) condition requiring a manual reboot. This vulnerability is due to trusting user input without validation. An attacker could exploit this vulnerability by sending crafted packets to the Remote Access SSL VPN server. A successful exploit could allow the attacker to cause the device to stop responding, resulting in a DoS condition.

Memory Leak

SSL VPN Memory Exhaust DoS on Cisco Secure Firewall ASA/FTD
CVE-2026-20105 7.7 - High - March 04, 2026

A vulnerability in the Remote Access SSL VPN functionality 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 exhaust device memory 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. An attacker could exploit this vulnerability by sending crafted 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.

Memory Leak

Cisco ASA/FTD Remote Access SSL VPN DoS via Memory Exhaustion
CVE-2026-20103 8.6 - High - March 04, 2026

A vulnerability in the Remote Access SSL VPN functionality of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Secure Firewall Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to exhaust device memory resulting in a denial of service (DoS) condition to new Remote Access SSL VPN connections. This does not affect the management interface, though it may become temporarily unresponsive. This vulnerability is due to trusting user input without validation. An attacker could exploit this vulnerability by sending crafted packets to the Remote Access SSL VPN server. A successful exploit could allow the attacker to cause the device web interface to stop responding, resulting in a DoS condition.

Allocation of Resources Without Limits or Throttling

Cisco Secure Firewall ASA/FTD SAML SSO DoS via Device Reload
CVE-2026-20101 8.6 - High - March 04, 2026

A vulnerability in the SAML 2.0 single sign-on (SSO) feature of Cisco Secure Firewall ASA Software and Secure FTD Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a DoS condition. This vulnerability is due to insufficient error checking when processing SAML messages. An attacker could exploit this vulnerability by sending crafted SAML messages to the SAML service. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Use of Insufficiently Random Values

LUA interpreter DoS via crafted HTTP on Cisco ASA VPN
CVE-2026-20100 7.7 - High - March 04, 2026

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.

Classic Buffer Overflow

Cisco Secure Firewall VPN Web Server DoS via Memory Leak
CVE-2026-20039 8.6 - High - March 04, 2026

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 cause a denial of service (DoS) condition on an affected device. This vulnerability is due to ineffective memory management of the VPN web server. An attacker could exploit this vulnerability by sending a large number of crafted HTTP requests to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Heap Inspection

Root Privilege Escalation via Lua Injection on Cisco Secure Firewall ASA/FTD
CVE-2026-20008 6 - Medium - March 04, 2026

A vulnerability in a small subset of CLI commands that are used on Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, local attacker to craft Lua code that could be used on the underlying operating system as root. This vulnerability exists because user-provided input is not properly sanitized. An attacker could exploit this vulnerability by crafting valid Lua code and submitting it as a malicious parameter for a CLI command. A successful exploit could allow the attacker to inject Lua code, which could lead to arbitrary code execution as the root user. To exploit this vulnerability, an attacker must have valid Administrator credentials.

Shell injection

Cisco ASA SSH Key Auth Bypass via Crafted Input
CVE-2026-20009 5.3 - Medium - March 04, 2026

A vulnerability in the implementation of the proprietary SSH stack with SSH key-based authentication in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to log in to a Cisco Secure Firewall ASA device and execute commands as a specific user. This vulnerability is due to insufficient validation of user input during the SSH authentication phase. An attacker could exploit this vulnerability by submitting crafted input during SSH authentication to an affected device. A successful exploit could allow the attacker to log in to the device as a specific user without the private SSH key of that user. To exploit this vulnerability, the attacker must possess a valid username and the associated public key. The private key is not required. Notes: Exploitation of this vulnerability does not provide the attacker with root access. The authentication, authorization, and accounting (AAA) configuration command auto-enable is not affected by this vulnerability.  

Improper Neutralization of Special Elements

Command Injection in Cisco FXOS/UCS Manager Web UI Elevates to Root
CVE-2026-20099 6.7 - Medium - February 25, 2026

A vulnerability in the web-based management interface of Cisco FXOS Software and Cisco UCS Manager Software could allow an authenticated, local attacker with administrative privileges to perform command injection attacks on an affected system and elevate privileges to root.  This vulnerability is due to insufficient input validation of command arguments supplied by the user. An attacker could exploit this vulnerability by authenticating to a device and submitting crafted input to the affected command. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system of the affected device with root-level privileges.

Shell injection

Cisco ASA/FTD Remote Code Execution via HTTP Input Validation
CVE-2025-20363 9 - Critical - September 25, 2025

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.

Heap-based Buffer Overflow

Cisco ASA/FTD VPN Web Server Unauth Read of Restricted URLs
CVE-2025-20362 6.5 - Medium - September 25, 2025

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.

AuthZ

Remote Code Execution in Cisco ASA VPN Web Server (CVE-2025-20333)
CVE-2025-20333 9.9 - Critical - September 25, 2025

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.

Classic Buffer Overflow

DoS via Infinite Loop in Cisco ASA/FTD DNS NAT Inspection
CVE-2025-20136 8.6 - High - August 14, 2025

A vulnerability in the function that performs IPv4 and IPv6 Network Address Translation (NAT) DNS inspection 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 an infinite loop condition that occurs when a Cisco Secure ASA or Cisco Secure FTD device processes DNS packets with DNS inspection enabled and the device is configured for NAT44, NAT64, or NAT46. An attacker could exploit this vulnerability by sending crafted DNS packets that match a static NAT rule with DNS inspection enabled through an affected device. A successful exploit could allow the attacker to create an infinite loop and cause the device to reload, resulting in a DoS condition.

Infinite Loop

CVE-2025-20237: Root Priv. Escalation via Cmd. Injection in Cisco ASA/FTD
CVE-2025-20237 6 - Medium - August 14, 2025

A vulnerability in Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying operating system with root-level privileges. To exploit this vulnerability, the attacker must have valid administrative credentials. This vulnerability is due to insufficient input validation of commands that are supplied by the user. An attacker could exploit this vulnerability by authenticating to a device and submitting crafted input for specific commands. A successful exploit could allow the attacker to execute commands on the underlying operating system as root.

Improper Neutralization of Expression/Command Delimiters

Cisco ASA SSL/TLS Handler DoS via Improper Error Handling
CVE-2020-27124 8.6 - High - November 18, 2024

A vulnerability in the SSL/TLS handler of Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause the affected device to reload unexpectedly, leading to a denial of service (DoS) condition. The vulnerability is due to improper error handling on established SSL/TLS connections. An attacker could exploit this vulnerability by establishing an SSL/TLS connection with the affected device and then sending a malicious SSL/TLS message within that connection. A successful exploit could allow the attacker to cause the device to reload.Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

Use of Uninitialized Variable

CrossSite Scripting in Cisco ASA/FTD VPN Web Client Services
CVE-2024-20382 6.1 - Medium - October 23, 2024

A vulnerability in the VPN web client services feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower 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 to application endpoints. An attacker could exploit this vulnerability by persuading a user to follow a link 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 web services page.

Cisco ASA/FTD SSL VPN DoS via crafted SSL/TLS
CVE-2024-20402 8.6 - High - October 23, 2024

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.

Cisco ASA/FTD Remote Access VPN TLS Key Validation DoS
CVE-2024-20495 - October 23, 2024

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 the device to reload unexpectedly, resulting in a denial of service (DoS) condition on an affected device. This vulnerability is due to improper validation of client key data after the TLS session is established. An attacker could exploit this vulnerability by sending a crafted key value to an affected system over the secure TLS session. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Cisco ASA SSH Server DoS via crafted SSH messages
CVE-2024-20526 5.3 - Medium - October 23, 2024

A vulnerability in the SSH server of Cisco Adaptive Security Appliance (ASA) Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition for the SSH server of an affected device. This vulnerability is due to a logic error when an SSH session is established. An attacker could exploit this vulnerability by sending crafted SSH messages to an affected device. A successful exploit could allow the attacker to exhaust available SSH resources on the affected device so that new SSH connections to the device are denied, resulting in a DoS condition. Existing SSH connections to the device would continue to function normally. The device must be rebooted manually to recover. However, user traffic would not be impacted and could be managed using a remote application such as Cisco Adaptive Security Device Manager (ASDM).

Allocation of Resources Without Limits or Throttling

Cisco ASA & FTD SNMP DoS via Authenticated Reload
CVE-2024-20268 - October 23, 2024

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 an unexpected reload of the device. This vulnerability is due to insufficient input validation of SNMP packets. An attacker could exploit this vulnerability by sending a crafted SNMP request to an affected device using IPv4 or IPv6. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability affects all versions of SNMP (versions 1, 2c, and 3) and requires a valid SNMP community string or valid SNMPv3 user credentials.

Cisco ASA SSH RCE: Authenticated User Gains Root Privileges
CVE-2024-20329 - October 23, 2024

A vulnerability in the SSH subsystem of Cisco Adaptive Security Appliance (ASA) Software could allow an authenticated, remote attacker to execute operating system commands as root. This vulnerability is due to insufficient validation of user input. An attacker could exploit this vulnerability by submitting crafted input when executing remote CLI commands over SSH. A successful exploit could allow the attacker to execute commands on the underlying operating system with root-level privileges. An attacker with limited user privileges could use this vulnerability to gain complete control over the system.

CVE-2024-20331: Cisco ASA/FTD Auth Entropy Leak Blocks VPN
CVE-2024-20331 5.9 - Medium - October 23, 2024

A vulnerability in the session authentication functionality of the Remote Access SSL VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to prevent users from authenticating. This vulnerability is due to insufficient entropy in the authentication process. An attacker could exploit this vulnerability by determining the handle of an authenticating user and using it to terminate their authentication session. A successful exploit could allow the attacker to force a user to restart the authentication process, preventing a legitimate user from establishing remote access VPN sessions.

Insufficient Entropy

XSS in Cisco ASA VPN Web Client Enables Script Execution
CVE-2024-20341 6.1 - Medium - October 23, 2024

A vulnerability in the VPN web client services feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower 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 to application endpoints. An attacker could exploit this vulnerability by persuading a user to follow a link 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 web services page.

XSS

Cisco ASA/FTD ACL Bypass via Active/Inactive Logic Error
CVE-2024-20293 - May 22, 2024

A vulnerability in the activation of an access control list (ACL) on Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to bypass the protection that is offered by a configured ACL on an affected device. This vulnerability is due to a logic error that occurs when an ACL changes from inactive to active in the running configuration of an affected device. An attacker could exploit this vulnerability by sending traffic through the affected device that should be denied by the configured ACL. The reverse condition is also truetraffic that should be permitted could be denied by the configured ACL. A successful exploit could allow the attacker to bypass configured ACL protections on the affected device, allowing the attacker to access trusted networks that the device might be protecting. Note: This vulnerability applies to both IPv4 and IPv6 traffic as well as dual-stack ACL configurations in which both IPv4 and IPv6 ACLs are configured on an interface.

Cisco ASA/FTD SAML 2.0 SSO Authorization Bypass Vulnerability
CVE-2024-20355 5 - Medium - May 22, 2024

A vulnerability in the implementation of SAML 2.0 single sign-on (SSO) for remote access VPN services in Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to successfully establish a VPN session on an affected device. This vulnerability is due to improper separation of authorization domains when using SAML authentication. An attacker could exploit this vulnerability by using valid credentials to successfully authenticate using their designated connection profile (tunnel group), intercepting the SAML SSO token that is sent back from the Cisco ASA device, and then submitting the same SAML SSO token to a different tunnel group for authentication. A successful exploit could allow the attacker to establish a remote access VPN session using a connection profile that they are not authorized to use and connect to secured networks behind the affected device that they are not authorized to access. For successful exploitation, the attacker must have valid remote access VPN user credentials.

Cisco ASA/FTD Local Auth PrivEsc via Restore Backup
CVE-2024-20358 6 - Medium - April 24, 2024

A vulnerability in the Cisco Adaptive Security Appliance (ASA) restore functionality that is available in Cisco ASA Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, local attacker to execute arbitrary commands on the underlying operating system with root-level privileges. Administrator-level privileges are required to exploit this vulnerability. This vulnerability exists because the contents of a backup file are improperly sanitized at restore time. An attacker could exploit this vulnerability by restoring a crafted backup file to an affected device. A successful exploit could allow the attacker to execute arbitrary commands on the underlying Linux operating system as root.

Shell injection

AnyConnect SSL VPN IP Spoofing via Improper Source IP Validation
CVE-2023-20275 4.3 - Medium - December 12, 2023

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.

Cisco ASA/FTD SSL VPN Auth Bypass via Cert Policy Failure
CVE-2023-20247 4.3 - Medium - November 01, 2023

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.

Cisco ASA/FTD AnyConnect SSL VPN DOS via Session Leak
CVE-2023-20042 8.6 - High - November 01, 2023

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.

Cisco ASA & FTD ACL Bypass via per-user-override Logic Error
CVE-2023-20256 5.8 - Medium - November 01, 2023

Multiple vulnerabilities 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 a configured access control list (ACL) and allow traffic that should be denied to flow through an affected device. These vulnerabilities are due to a logic error that could occur when the affected software constructs and applies per-user-override rules. An attacker could exploit these vulnerabilities by connecting to a network through an affected device that has a vulnerable configuration. A successful exploit could allow the attacker to bypass the interface ACL and access resources that would should be protected.

Cisco ASA/FTD VPN AAA Separation Vulnerability (9.16)
CVE-2023-20269 5 - Medium - September 06, 2023

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.

Authentication Bypass Using an Alternate Path or Channel

Cisco ASA/FTD/IOS DHCPv6 Client DoS via Unauth Message
CVE-2023-20081 5.9 - Medium - March 23, 2023

A vulnerability in the IPv6 DHCP (DHCPv6) client module of Cisco Adaptive Security Appliance (ASA) Software, Cisco Firepower Threat Defense (FTD) Software, Cisco IOS Software, and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to insufficient validation of DHCPv6 messages. An attacker could exploit this vulnerability by sending crafted DHCPv6 messages to an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition. Note: To successfully exploit this vulnerability, the attacker would need to either control the DHCPv6 server or be in a man-in-the-middle position.

Memory Corruption

Cisco ASA/FTD SNMP DoS via Authenticated Remote Exploit
CVE-2022-20924 6.5 - Medium - November 15, 2022

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.

Improper Input Validation

Cisco ASA/FTD DAP HostScan Triggered DoS Reload Vulnerability
CVE-2022-20947 7.5 - High - November 15, 2022

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.