CVE-2019-1884: Cisco Asyncos

Medium severity, CVSS 6.5. EPSS: 1.5% chance of exploitation in the next 30 days.

A vulnerability in the web proxy functionality of Cisco AsyncOS Software for Cisco Web Security Appliance (WSA) could allow an authenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to insufficient input validation mechanisms for certain fields in HTTP/HTTPS requests sent through an affected device. A successful attacker could exploit this vulnerability by sending a malicious HTTP/HTTPS request through an affected device. An exploit could allow the attacker to force the device to stop processing traffic, resulting in a DoS condition.

Affected products

• Cisco Asyncos: from 10.1, before 10.5.5-005 (fixed in 10.5.5-005); from 11.5, before 11.5.2-020 (fixed in 11.5.2-020); from 11.7, before 11.7.0-407 (fixed in 11.7.0-407)
• Cisco Web Security Appliance: version 10.1.4-017 only; version 10.5.2-072 only; version 11.5.1-fcs-125 only; version 11.7.0-256 only

Published 2019-07-04. Last modified 2026-06-17.