Cisco Web Security Appliance Malformed Request Denial of Service Vulnerability

Description

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.

Scores

EPSS (exploitation in 30 days)

1.8% · top 22% of all CVEs (4 Nov 2026)

CISA SSVC

Exploitation: none · Automatable: yes · Technical impact: partial

The list uses the assigner's score when there is one, then CISA's, then NVD's: High 8.6.

Weakness

• CWE-20 (opens in a new tab)All about CWE-20 and its CVEs

Affected products

• Cisco · Cisco Web Security Appliance (WSA)

  • affected unspecified – < 11.5.2-020
  • affected unspecified – < 11.7.0-406

What to do

Exploitation: The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

References (1)

• 20190501 Cisco Web Security Appliance Malformed Request Denial of Service Vulnerability (opens in a new tab)vendor-advisoryx_refsource_CISCOx_transferred

Sources

The same CVE in the primary databases and aggregators, to check against.

• CVE.org record (opens in a new tab)
• CVE List JSON (GitHub) (opens in a new tab)
• NVD (opens in a new tab)
• FIRST EPSS (opens in a new tab)
• OSV.dev (opens in a new tab)
• GitHub Advisories (opens in a new tab)
• CIRCL Vulnerability-Lookup (opens in a new tab)

Badge for a README or a ticket

[![CVE-2019-1817](https://trackcve.app/badge/CVE-2019-1817.svg)](https://trackcve.app/cve/CVE-2019-1817)

Record last updated 19 Nov 2024, 19:08 UTC.