How severe is CVE-2025-20333?

CVE-2025-20333 has a CVSS score of 9.9/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2025-20333?

Affected package information for CVE-2025-20333 is not yet fully mapped. Check the official advisory links for details.

How do I fix CVE-2025-20333?

No fixed version has been published for CVE-2025-20333 yet. Monitor the advisory for updates, apply mitigations recommended by the vendor, and use O3 Security to track when a fix becomes available in your stack.

Is CVE-2025-20333 actively exploited in the wild?

No public exploit code has been indexed for CVE-2025-20333 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2025-20333?

CVE-2025-20333 has an EPSS (Exploit Prediction Scoring System) score of 26.6%, placing it in the 96th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score warrants monitoring and prompt remediation.

Is CVE-2025-20333 in the CISA Known Exploited Vulnerabilities catalog?

Yes. CVE-2025-20333 (Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability) was added to CISA's Known Exploited Vulnerabilities (KEV) catalog on 2025-09-25. CISA required all US federal civilian agencies to remediate this vulnerability by 2025-09-26. The required action was: The KEV due date refers to the deadline by which FCEB agencies are expected to review and begin implementing the guidance outlined in Emergency Directive (ED) 25-03 (URL listed below in Notes). Agencies must follow the mitigation steps provided by CISA (URL listed below in Notes) and vendor’s instructions (URL listed below in Notes). Adhere to the applicable BOD 22-01 guidance for cloud services or discontinue use of the product if mitigations are not available. Being listed in the KEV catalog is the strongest possible confirmation of active exploitation — treat this as a critical priority.

What type of vulnerability is CVE-2025-20333?

CVE-2025-20333 is classified as CWE-120 (CWE-120). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

Which products and versions are affected by CVE-2025-20333?

CVE-2025-20333 affects cisco adaptive security appliance software; cisco firepower threat defense (1 version, e.g. 7.6.0). Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2025-20333 published, and has it been updated?

CVE-2025-20333 was published on September 25, 2025 and was last updated on October 28, 2025. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

CVE-2025-20333: Adaptive Security Appliance Software CWE-120 (C…

EPSS Exploitation Probability

via FIRST.org ↗

26.6%probability of exploitation in next 30 days

Moderate Risk96th percentile-3.24%

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Description

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.

Affected Products

2 products · 12 configurations

OS

adaptive security appliance softwarecisco

≥ 9.22 && < 9.22.1.3

range

Application

firepower threat defensecisco

≥ 7.3.0 && < 7.4.2.4

1 version

7.6.0

Frequently Asked Questions

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 complet

O3 Security · Impact-Aware SCA

Is CVE-2025-20333 in your stack?

O3 detects CVE-2025-20333 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

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