CVE-2021-23885: Privilege Escalation in McAfee Web Gateway

The impact of CVE-2021-23885 is severe. An attacker who can successfully exploit this vulnerability can gain administrative access to the McAfee Web Gateway appliance. This allows them to modify configurations, install malicious software, steal sensitive data, and potentially pivot to other systems on the network. The ability to execute commands directly on the appliance significantly expands the attack surface and increases the potential for data breaches and system disruption. This vulnerability is particularly concerning given the role of MWG in filtering web traffic and protecting organizations from external threats; a compromised MWG could be used to bypass security controls and deliver malware.

1. Reserved2021-01-12
2. Published2021-02-17
3. Modified2024-08-03
4. EPSS updated2026-04-02

The primary mitigation for CVE-2021-23885 is to upgrade McAfee Web Gateway to version 9.2.8 or later. If immediate upgrading is not possible due to compatibility concerns or testing requirements, consider implementing stricter access controls to the troubleshooting page, limiting access to only authorized personnel. Review and audit user permissions within MWG to ensure least privilege principles are followed. Monitor MWG logs for suspicious activity, particularly attempts to access or manipulate the troubleshooting page. While a direct WAF rule is difficult to implement, consider implementing general input validation rules to prevent injection attacks.