CVE-2023-20269
Cisco Adaptive Security Appliance and Firepower Threat Defense Unauthorized Access Vulnerability
Published Sep 6, 2023 · updated Aug 11, 2026 · cisco adaptive security appliance software
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.
Timeline
Detection, updates, and resolution for this record.
Sep 6, 2023 · Catalog
Detected
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 us
Sep 13, 2023 · CISA KEV
Known exploited
Apply mitigations per vendor instructions for group-lock and vpn-simultaneous-logins or discontinue use of the product for unsupported devices.
Oct 4, 2023 · CISA KEV
Remediation due
Apply mitigations per vendor instructions for group-lock and vpn-simultaneous-logins or discontinue use of the product for unsupported devices.
Aug 11, 2026 · Catalog
Updated
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 us
Required action
Apply mitigations per vendor instructions for group-lock and vpn-simultaneous-logins or discontinue use of the product for unsupported devices.
CISA due date Oct 4, 2023
Affected
- cpe cisco/adaptive security appliance software9.8.1
- cpe cisco/adaptive security appliance software9.8.1.5
- cpe cisco/adaptive security appliance software9.8.1.7
- cpe cisco/adaptive security appliance software9.8.2
- cpe cisco/adaptive security appliance software9.8.2.14
- cpe cisco/adaptive security appliance software9.8.2.15
- cpe cisco/adaptive security appliance software9.8.2.17
- cpe cisco/adaptive security appliance software9.8.2.8
- cpe cisco/secure firewall threat defense6.2.3
- vendor Cisco Adaptive Security Appliance and Firepower Threat Defenseversion unspecified
Sources
- CISA KEVCVE-2023-20269
Cisco Adaptive Security Appliance and Firepower Threat Defense contain an unauthorized access vulnerability that could allow an unauthenticated, remote attacker to conduct a brute force attack in an attempt to identify valid username and password combinations or establish a clientless SSL VPN session with an unauthorized user.
cisa.gov - CVE.orgCVE-2023-20269
Official CVE identifier
cve.org - FIRST EPSSCVE-2023-20269
30-day exploitation probability 25.5%
first.org - NIST NVDCVE-2023-20269
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 pass
nvd.nist.gov