CVE-2019-1817: Cisco Web Security Appliance

High severity, CVSS 7.5. EPSS: 1.8% chance of exploitation in the next 30 days.

A vulnerability in the web proxy functionality of Cisco AsyncOS Software for Cisco Web Security Appliance could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to improper validation of HTTP and HTTPS requests. An attacker could exploit this vulnerability by sending a malformed HTTP or HTTPS request to an affected device. An exploit could allow the attacker to cause a restart of the web proxy process, resulting in a temporary DoS condition.

Affected products

• Cisco Web Security Appliance: version 11.5.1-fcs-115 only; version 11.5.1-fcs-124 only; version 11.5.1-fcs-125 only; version 11.7.0-fcs-334 only

Published 2019-05-03. Last modified 2026-06-17.