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

Summary

Advisory CVE-2025-20333. Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Buffer Overflow Vulnerability Vendor: Cisco. Source: CVE. Threat: high. CVSS 0. Known exploited in the wild. See the…

What to do

General, cautious steps (verify details in the official source):

• Prioritize patching or mitigation immediately (treat as actively risky).
• Identify affected product versions in your inventory and verify whether you are impacted.
• Apply vendor patches/updates or recommended mitigations as soon as available.
• Check logs/telemetry for indicators of compromise and suspicious activity.
• Consider temporary hardening: restrict access, reduce attack surface, and monitor aggressively.
• Read the official advisory for exact affected versions and remediation steps.

Official advisory

Read the official source

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