Cisco Adaptive Security Appliance and Firepower Threat Defense Unauthorized Access Vulnerability
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…
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 4 / 5
- KEV catalog (CISA)13 Sept 2023
- Exploited in EUVD (ENISA)13 Sept 2023
- Used by ransomwareyes
- EPSS above 10 %26.6%
- No account, over the networkno
What to do
Fix
Apply the vendor’s fix as soon as it is available.
CISA guidance: Apply mitigations per vendor instructions for group-lock and vpn-simultaneous-logins or discontinue use of the product for unsupported devices.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Description ENISA EUVD
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.
Affected products
- 6.2.3.3
- 7.0.1.1
- 9.17.1
- 9.14.3.15
- 9.17.1.30
- 9.8.4.25
- 9.8.2.38
- 9.12.4.52
- 9.12.4.41
- 9.12.4.10
- 6.4.0.4
- 9.14.3
Open source packages OSV
Affected libraries according to OSV, with fixed versions.
Timeline
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Published
-
Exploitation reported (ENISA)
-
Added to the KEV catalog
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CISA remediation due date
-
EPSS peak: 26.6%
References
Other exploited vulnerabilities from the same vendor
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