Applied Cybernetics Group
Threat intel → detection pipeline
Friday, September 18, 2026
Data as of 13:09 UTC

Cisco Adaptive Security Appliance (ASA) Denial-of-Service Vulnerability

Added to KEV
2021-11-03
Federal due date
2022-05-03
Vendor
Cisco
Product
Adaptive Security Appliance (ASA)
EPSS
100.0th percentile (score 0.999, as of 2026-09-16)
NVD CVSS v3.1
7.5 (HIGH)
Ransomware use
Unknown
ATT&CK
T1005 , T1202 · signal rollup
Upstream
https://nvd.nist.gov/vuln/detail/CVE-2018-0296

CISA short description

Cisco Adaptive Security Appliance (ASA) contains an improper input validation vulnerability with HTTP URLs. Exploitation could allow an attacker to cause a denial-of-service (DoS) condition or information disclosure.

Required action

Apply updates per vendor instructions.

NVD description

A vulnerability in the web interface of the Cisco Adaptive Security Appliance (ASA) could allow an unauthenticated, remote attacker to cause an affected device to reload unexpectedly, resulting in a denial of service (DoS) condition. It is also possible on certain software releases that the ASA will not reload, but an attacker could view sensitive system information without authentication by using directory traversal techniques. The vulnerability is due to lack of proper input validation of the HTTP URL. An attacker could exploit this vulnerability by sending a crafted HTTP request to an affected device. An exploit could allow the attacker to cause a DoS condition or unauthenticated disclosure of information. This vulnerability applies to IPv4 and IPv6 HTTP traffic. This vulnerability affects Cisco ASA Software and Cisco Firepower Threat Defense (FTD) Software that is running on the following Cisco products: 3000 Series Industrial Security Appliance (ISA), ASA 1000V Cloud Firewall, ASA 5500 Series Adaptive Security Appliances, ASA 5500-X Series Next-Generation Firewalls, ASA Services Module for Cisco Catalyst 6500 Series Switches and Cisco 7600 Series Routers, Adaptive Security Virtual Appliance (ASAv), Firepower 2100 Series Security Appliance, Firepower 4100 Series Security Appliance, Firepower 9300 ASA Security Module, FTD Virtual (FTDv). Cisco Bug IDs: CSCvi16029.

EPSS percentile is the FIRST.org exploit-probability ranking as of the date noted above; it moves daily. CVSS reflects NVD's analysis at time of publication.