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Cisco Bug: CSCvs66918 - Cisco Email Security Appliance URL Filtering Bypass Vulnerability

Last Modified

Aug 17, 2020

Products (1)

  • Cisco Email Security Appliance

Known Affected Releases

12.1-089 12.5.0-066

Description (partial)

Symptom:
A vulnerability in the antispam protection mechanisms of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass the URL reputation filters on an affected device.

The vulnerability is due to insufficient input validation of URLs. An attacker could exploit this vulnerability by crafting the URL in a particular way. A successful exploit could allow the attacker to bypass the URL reputation filters that are configured for the affected device, which could allow malicious URLs to pass through the device.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-url-bypass-WO4BZ75s

Conditions:
At the time of publication, this vulnerability affected Cisco AsyncOS Software for Cisco ESA releases earlier than Release 13.5.0.
At the time of publication, Cisco AsyncOS Software for Cisco ESA releases 13.5.0 and later contained the fix for this vulnerability.
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