Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) Heap Inspection Vulnerability
Cisco · Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD)
What it is
Cisco Secure Firewall Adaptive Security Appliance (ASA) and Secure Firewall Threat Defense (FTD) contain a heap inspection vulnerability that could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition.
Why we say that
- CISA's federal remediation deadline (2026-08-14) has passed
- Listed in the CISA Known Exploited Vulnerabilities catalogue
Every line above comes from a named public source. Where the evidence is thin, we say so rather than inventing confidence — see methodology.
What to do
Apply mitigations in accordance with vendor instructions, ensuring compliance with CISA’s BOD 26-04 Prioritizing Security Updates Based on Risk (see URL in Notes) guidance and CISA’s “Forensics Triage Requirements” (see URL in Notes). Follow applicable BOD 26-04 guidance for cloud services or discontinue use of the product if mitigations are unavailable. Stakeholders are responsible for evaluating each asset's internet exposure and ensuring adherence to BOD 26-04 patching guidelines.
What it costs when this goes wrong
This is where UK enforcement meets the vulnerability record. Where an unfixed vulnerability leads to a breach, the ICO treats it as a security failure under UK GDPR. Recent cases:
- The Electoral Commission Reprimand issued to the Electoral Commission in respect of Articles 5(1)(f) and 32(1)(b). Between 24 August 2021 and 27 October 20…
- Gain Capital UK Limited Gain Capital UK have been issued a Reprimand in respect of Articles 32 (2) and 32 (1) (b). An unauthorised third party leveraged a…
- Chartered Institute for Securities & Investment An unauthorised third party exploited a known vulnerability in the Sitefinity software to leverage a bruteforce attack to upload a…