A vulnerability in the Secure Sockets Layer (SSL) Virtual Private Network (VPN) Client Certificate Authentication feature for Cisco Adaptive

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

• cisco adaptive security appliance software9.4.4 and later · up to 9.4.4.13 inclusive
• cisco adaptive security appliance software9.5.3.7 and later · up to 9.5.3.9 inclusive
• cisco adaptive security appliance software9.6.2.9 and later · up to 9.6.2.21 inclusive
• cisco adaptive security appliance software9.6.3 and later · up to 9.6.3.17 inclusive
• cisco adaptive security appliance software9.4.3.1
• cisco adaptive security appliance software9.4.3.2
• cisco adaptive security appliance software9.5.2.7
• cisco adaptive security appliance software9.5.2.8

Versions reported by the vendor

Affected version ranges reported by the assigning authority (cisco). Independent of NVD's CPE analysis and usually ahead of it.

• n/a Cisco Adaptive Security Appliance

  • Cisco Adaptive Security Applianceaffected

Other highest-scoring records for the same primary product.

• CVE-2025-20362Update: On November 5, 2025, Cisco became aware of a new attack variant against devices running Cisco Secure ASA Software or Cisco Secure FTKEV
  90Now
• CVE-2025-20333A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat DKEV
  90Now
• CVE-2020-3452Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software Web Services Read-Only Path Traversal VulnerabilityKEV
  90Now
• CVE-2018-0296A vulnerability in the web interface of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to causeKEV
  90Now
• CVE-2024-20353A vulnerability in the management and VPN web servers for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat DefensKEV
  85Now
• CVE-2023-20269A vulnerability in the remote access VPN feature of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTDKEV
  74This week

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Root cause

A certificate validation error is silently swallowed instead of terminating the connection. Often, code added for a test environment makes its way into production.

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

1override fun checkServerTrusted(chain: Array<X509Certificate>, type: String) {2  // Left empty for the test environment3}

1val client = OkHttpClient.Builder()2  .certificatePinner(3    CertificatePinner.Builder()4      .add("api.sirius.example", "sha256/…")5      .build()6  ).build()

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.