Cisco Web Security Appliance Filter Bypass Vulnerability

Description

A vulnerability in the Web-Based Reputation Score (WBRS) engine of Cisco AsyncOS Software for Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to bypass established web request policies and access blocked content on an affected device. This vulnerability is due to incorrect handling of certain character combinations inserted into a URL. An attacker could exploit this vulnerability by sending crafted URLs to be processed by an affected device. A successful exploit could allow the attacker to bypass the web proxy and access web content that has been blocked by policy.

Scores

EPSS (exploitation in 30 days)

0.93% · top 39% of all CVEs (6 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: Medium 5.8.

Weakness

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

Affected products

• Cisco · Cisco Web Security Appliance (WSA)

  • affected n/a

What to do

Exploitation: The Cisco PSIRT is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.

References (1)

• 20220406 Cisco Web Security Appliance Filter Bypass 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-2022-20784](https://trackcve.app/badge/CVE-2022-20784.svg)](https://trackcve.app/cve/CVE-2022-20784)

Record last updated 6 Nov 2024, 16:29 UTC.