VULNERABILITY INTELLIGENCE

CVE-2021-34741

CVSS score7.5 HIGH
EPSS probability1.29%
CISA KEVNot currently listed
Published2021-11-04
Last modified2026-06-17
CVSS vectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Description

A vulnerability in the email scanning algorithm of Cisco AsyncOS software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to perform a denial of service (DoS) attack against an affected device. This vulnerability is due to insufficient input validation of incoming emails. An attacker could exploit this vulnerability by sending a crafted email through Cisco ESA. A successful exploit could allow the attacker to exhaust all the available CPU resources on an affected device for an extended period of time, preventing other emails from being processed and resulting in a DoS condition.

Weakness classification

  • psirt@cisco.com: CWE-770
  • nvd@nist.gov: CWE-770

Primary references