CVE-2025-20333: Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability

Published Sep 25, 2025
·
Updated

A vulnerability in the VPN web server of Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software could allow an authenticated, remote attacker to execute arbitrary code on an affected device. This vulnerability is due to improper validation of user-supplied input in HTTP(S) requests. An attacker with valid VPN user credentials could exploit this vulnerability by sending crafted HTTP requests to an affected device. A successful exploit could allow the attacker to execute arbitrary code as root, possibly resulting in the complete compromise of the affected device.

Other sources

Cisco Secure Firewall Adaptive Security (ASA) Appliance and Secure Firewall Threat Defense (FTD) Software VPN Web Server contain a buffer overflow vulnerability that allows for remote code execution. This vulnerability could be chained with CVE-2025-20362.

CISA

Affected Software

15 affected components
Cisco Secure Firewall Adaptive Security Appliance (ASA) Software
Cisco Secure Firewall Threat Defense (FTD) Software
Cisco Secure Firewall Adaptive Security Appliance and Secure Firewall Threat Defense
Cisco Adaptive Security Appliance Software>=9.12<9.12.4.72
Cisco Adaptive Security Appliance Software>=9.14<9.14.4.28
Cisco Adaptive Security Appliance Software>=9.16<9.16.4.85
Cisco Adaptive Security Appliance Software>=9.17.0<9.17.1.45
Cisco Adaptive Security Appliance Software>=9.18<9.18.4.47
Cisco Adaptive Security Appliance Software>=9.19<9.19.1.37
Cisco Adaptive Security Appliance Software>=9.20<9.20.3.7
Cisco Adaptive Security Appliance Software>=9.22<9.22.1.3
Cisco Secure Firewall Threat Defense>=7.0.0<7.0.8.1
Cisco Secure Firewall Threat Defense>=7.1.0<7.2.9
Cisco Secure Firewall Threat Defense>=7.3.0<7.4.2.4
Cisco Secure Firewall Threat Defense=7.6.0

Event History

Sep 25, 2025
CVE Published
via CISA·12:00 AM
Known Exploited
via CISA·12:00 AM
Data Sourced
via CISA·12:00 AM
RemedyDescriptionAffected Software
CVE Published
via MITRE·04:12 PM
Data Sourced
via MITRE·04:12 PM
DescriptionSeverityWeakness
Data Sourced
via NVD·04:15 PM
DescriptionSeverityWeaknessAffected Software
News Published
via BleepingComputer·04:49 PM
News Published
via BleepingComputer·04:50 PM
News Published
via BleepingComputer·05:52 PM
Sep 26, 2025
News Published
via The Register·10:22 AM
News Published
via The Register·10:28 AM
Sep 27, 2025
News Published
via The Register·11:06 AM
Sep 30, 2025
News Published
via The Register·04:09 PM
News Published
via BleepingComputer·04:58 PM
Oct 16, 2025
News Published
via The Register·12:44 PM
Nov 6, 2025
News Published
via BleepingComputer·01:31 PM
News Published
via The Register·06:51 PM
Nov 7, 2025
News Published
via BleepingComputer·03:44 PM
Nov 13, 2025
News Published
via BleepingComputer·12:05 PM
Jan 9, 2026
News Published
via BleepingComputer·03:46 AM
Apr 24, 2026
News Published
via The Register·02:46 PM
News Published
via BleepingComputer·08:34 PM
May 6, 2026
News Published
via BleepingComputer·06:06 PM
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Frequently Asked Questions

1

What is the severity of CVE-2025-20333?

CVE-2025-20333 has been assigned a high severity rating due to its potential for remote code execution.

2

How do I fix CVE-2025-20333?

To fix CVE-2025-20333, update the Cisco Secure Firewall ASA or FTD software to the latest patched version.

3

What systems are affected by CVE-2025-20333?

CVE-2025-20333 affects Cisco Secure Firewall Adaptive Security Appliance (ASA) Software and Cisco Secure Firewall Threat Defense (FTD) Software.

4

Can CVE-2025-20333 be exploited remotely?

Yes, CVE-2025-20333 can be exploited by an authenticated remote attacker.

5

What type of vulnerability is CVE-2025-20333?

CVE-2025-20333 is a code execution vulnerability in the VPN web server of affected Cisco devices.

Contact

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