CVE-2019-15971: Cisco Email Security Appliance Firmware

Medium severity, CVSS 4.3. EPSS: 0.5% chance of exploitation in the next 30 days.

A vulnerability in the MP3 detection engine of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass configured content filters on the device. The vulnerability is due to improper validation of certain MP3 file types. An attacker could exploit this vulnerability by sending a crafted MP3 file through the targeted device. A successful exploit could allow the attacker to bypass configured content filters that would normally drop the email.

Affected products

• Cisco Email Security Appliance Firmware: before 13.0 (fixed in 13.0)

Published 2019-11-26. Last modified 2026-06-17.