CVE-2019-1693: Cisco Adaptive Security Appliance Software and Firepower Threat Defense Software WebVPN Denial of Service Vulnerability

Severity: medium (CVSS 6.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2019-05-03 · updated 2026-08-11
Weakness: CWE-399

Description

A vulnerability in the WebVPN service of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper management of authenticated sessions in the WebVPN portal. An attacker could exploit this vulnerability by authenticating with valid credentials and accessing a specific URL in the WebVPN portal. A successful exploit could allow the attacker to cause the device to reload, resulting in a temporary DoS condition.

Affected products

Cisco ASA Software: before 9.4.4.34; from 9.5 before 9.6.4.25; from 9.7 before 9.8.4; from 9.9 before 9.9.2.50; from 9.10 before 9.10.1.17 — fixed in 9.10.1.17, 9.4.4.34, 9.6.4.25, 9.8.4, 9.9.2.50
Cisco Firepower Threat Defense Software: from 6.2.1 before 6.2.3.12; from 6.3.0 before 6.3.0.3 — fixed in 6.2.3.12, 6.3.0.3

How to fix

Upgrade to a fixed version: Cisco ASA Software 9.10.1.17, 9.4.4.34, 9.6.4.25, 9.8.4; Cisco Firepower Threat Defense Software 6.2.3.12, 6.3.0.3. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2019-1693 or the next vulnerability affects your stack