Cisco Secure Email Gateway Email Filter Bypass Vulnerability

A vulnerability in the email filtering mechanism of Cisco Secure Email Gateway could allow an unauthenticated, remote attacker to bypass the configured rules and allow emails that should have been denied to flow through an affected device.  

This vulnerability is due to improper handling of email that passes through an affected device. An attacker could exploit this vulnerability by sending a crafted email through the affected device. A successful exploit could allow the attacker to bypass email filters on the affected 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://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-mailpol-bypass-5nVcJZMw

Security Impact Rating: Medium

CVE: CVE-2025-20153

Source:: Cisco Security Advisories