CVE-2021-1534 MEDIUM

CVE-2021-1534: Cisco Email Security Appliance URL Filtering Bypass Vulnerability

Vendor Cisco
Product Cisco Email Security Appliance (ESA)
Weakness CWE-20 · Input validation
Published October 6, 2021
Last update November 7, 2024

CVSS base score

5.8/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity Low

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N

What the vulnerability does

01Description

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

Key dates

02Disclosure timeline

October 6, 2021 CVE published
November 7, 2024 Record updated