Cisco Adaptive Security Appliance and Firepower Threat Defense Unauthorized Access Vulnerability

A remote attacker, with a low-privilege account, can achieve partial data exposure, partial data tampering. CISA has confirmed use of this vulnerability in known ransomware campaigns — treat as high priority for remediation. Federal agencies are required to remediate by 2023-10-04 under CISA BOD 22-01.

This is a Authentication Bypass (CWE-288) vulnerability in Cisco Adaptive Security Appliance and Firepower Threat Defense. 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. Exploitation requires remote network access, low attack complexity, a low-privilege authenticated account, and no user interaction required.

Probably yes if any of these apply:

CISA confirms this CVE has been used in known ransomware campaigns. Added to the KEV catalog on 2023-09-13; federal agencies required to remediate by 2023-10-04.