1. Cleus
  2. Zero-days
  3. CVE-2025-20362
Exploited in the wildVPNs, firewalls & gatewaysWork IT

CVE-2025-20362 Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense: login or permission bypass

In plain words: A door that should be locked is not: part of the system can be reached without a valid login or permission. The attacker gets in as a user or administrator without knowing a password.

Confirmed exploited by CISA on · US federal patch deadline Sep 26, 2025

What to do

  1. Install Cisco's security update for Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense. If no update exists, follow the vendor's workaround or stop using the product until one ships.
  2. Patch edge devices first — attackers often start scanning for them within hours of a fix.
  3. Never expose the device's admin page to the internet.
  4. After patching a device that was exposed, follow the vendor's compromise checks, end active sessions and change passwords.

Read Cisco's advisory ↗

Who is affected

Work IT. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

What's at risk: They face the internet and guard the whole network, so a flaw here can hand attackers a way in — and these devices usually run no antivirus, so break-ins go unnoticed.

The details

Official name
Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Missing Authorization Vulnerability
Product
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense
CISA description
Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Software VPN Web Server contain a missing authorization vulnerability. This vulnerability could be chained with CVE-2025-20333.
Type of flaw
Login or permission bypass (CWE-862)
Confirmed exploited
Sep 25, 2025
US federal patch deadline
Sep 26, 2025

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Answering about CVE-2025-20362 ·

Questions about CVE-2025-20362

Is CVE-2025-20362 being exploited?

Yes. CISA added CVE-2025-20362 to its Known Exploited Vulnerabilities catalog on Sep 25, 2025, which means there is reliable evidence of real-world attacks.

How do I fix CVE-2025-20362?

Install Cisco's security update for Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense. If no update exists, follow the vendor's workaround or stop using the product until one ships. Patch edge devices first — attackers often start scanning for them within hours of a fix.

Am I affected by CVE-2025-20362?

Only if you use Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense. Aimed mostly at company systems — you are affected through the companies you use, not your own phone.

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