Cisco ASA and FTD Denial of Service Vulnerability
A vulnerability in the management and VPN web servers for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload…
Severity = CVSS. Probability = EPSS (FIRST). Exploitation = public signals: KEV, EUVD, ransomware, EPSS above 10 %, no account required.
Exploitation probability EPSS · FIRST
Exploitation signals 4 / 5
- KEV catalog (CISA)24 Apr 2024
- Exploited in EUVD (ENISA)24 Apr 2024
- Used by ransomwareno
- EPSS above 10 %69.8%
- No account, over the networkyes
What to do
Fix
Apply the vendor’s fix as soon as it is available.
CISA guidance: Apply mitigations per vendor instructions or discontinue use of the product if mitigations are unavailable.
Meanwhile
Take the service off the internet or restrict access to it, watch the logs and look for signs of compromise.
Manufacturers (CRA)
Exploited vulnerability in your product: early warning to ENISA within 24 h, then notification within 72 h (Article 14 of the Cyber Resilience Act). The CRA explained
Description ENISA EUVD
A vulnerability in the management and VPN web servers for Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause the device to reload unexpectedly, resulting in a denial of service (DoS) condition. This vulnerability is due to incomplete error checking when parsing an HTTP header. An attacker could exploit this vulnerability by sending a crafted HTTP request to a targeted web server on a device. A successful exploit could allow the attacker to cause a DoS condition when the device reloads.
Affected products
- 9.12.4.4
- 9.12.4
- 9.8.2.15
- 9.8.2.8
- 6.6.3
- 9.18.4
- 9.16.2.3
- 9.16.3.19
- 9.16.4.42
- 9.14.4.22
- 9.8.3.18
- 9.14.1.19
Open source packages OSV
Affected libraries according to OSV, with fixed versions.
Timeline
-
Published
-
Exploitation reported (ENISA)
-
Added to the KEV catalog
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CISA remediation due date
-
EPSS peak: 70.7%
References
Other exploited vulnerabilities from the same vendor
- CVE-2026-76418Cisco Secure Firewall ASA Software and Cisco Secure FTD Software Unchecked Return Value to NULL Pointer Dereference Vulnerability5.3 · Rising fast
- CVE-2026-76519Cisco Secure Email Gateway Relative Path Traversal Vulnerability5.8 · Rising fast
- CVE-2026-76504Cisco Catalyst SD-WAN Manager Hex Encoding Vulnerability7.5 · Actively exploited
- CVE-2026-76460Cisco Identity Services Engine Incorrect Use of Privileged APIs Vulnerability8.7 · Actively exploited
- CVE-2026-76461Cisco Secure Email Gateway SQL Injection Vulnerability7.2 · Actively exploited
- CVE-2026-20079Cisco Firewall Management Center Authentication Bypass Using an Alternate Path or Channel Vulnerability9.1 · Actively exploited