CVE-2022-20784
mediumpriority · track · 21EPSS 0.009 · 61 %ileEURUUSEPSS · scored 2026-10-27
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.
remediations
Vendor fix, mitigation, or workaround guidance, as published by each source.
A vendor fix is available.
- FixedCisco Secure Web Appliancecisco_csaf
Cisco has released software updates that address this vulnerability.
https://software.cisco.com
cvss
Technical severity, 0–10. One row per scoring source.
base score 0–10 · higher = more severe · hover a vector to decode
ssvc
A stakeholder decision — act, attend, or track — from exploitation and impact.
weaknesses
The CWE weakness classes this flaw belongs to.
affected products (4)
Products and version ranges known to be affected.
- cisco web security appliance11.7.0 → 14.0.2nvdUScpe:2.3:a:cisco:web_security_appliance:*:*:*:*:*:*:*:*
advisories (1)
Vendor and ecosystem advisories describing this.
- cisco-sa-swa-filter-bypass-XXXTU3XCisco Web Security Appliance Filter Bypass Vulnerability2022-04-06csaf · cisco_csafUS
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. Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.
also known as (5)
Other names and identifiers for this entity.
sources
Which sources assert this record, and when.
references (6)
External citations — patches, advisories, analysis.
- https://cxsecurity.com/cveshow/CVE-2022-20784/cnnvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-swa-filter-bypass-XXXTU3Xcnnvd
- https://vigilance.fr/vulnerability/Cisco-WSA-egress-filtrering-bypass-via-WBRS-37991cnnvd
- https://www.cybersecurity-help.cz/vdb/SB2022040625cnnvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-swa-filter-bypass-XXXTU3Xenisa_euvd
- https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-swa-filter-bypass-XXXTU3XVendor Advisorynvd
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