CVE-2020-7250 in Endpoint Security
Summary
by MITRE
Symbolic link manipulation vulnerability in McAfee Endpoint Security (ENS) for Windows prior to 10.7.0 February 2020 Update allows authenticated local user to potentially gain an escalation of privileges by pointing the link to files which the user which not normally have permission to alter via carefully creating symbolic links from the ENS log file directory.
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Analysis
by VulDB Data Team • 05/27/2024
This vulnerability resides in McAfee Endpoint Security for Windows software where an authenticated local user can manipulate symbolic links to escalate privileges. The flaw exists within the handling of log file directories where symbolic links can be created to point to protected system files that the user normally lacks permissions to modify. The vulnerability stems from insufficient validation of symbolic link targets during file operations, allowing malicious users to redirect write operations to sensitive system locations. This represents a classic privilege escalation vector that leverages the principle of least privilege violation by exploiting improper access controls. The issue is particularly concerning because it requires only local authentication, making it accessible to any user with legitimate system access who can create symbolic links in the targeted directory structure. The vulnerability affects versions prior to the February 2020 update, indicating that McAfee had identified this weakness and implemented a fix in their subsequent release.
The technical implementation of this vulnerability involves the manipulation of symbolic links within the ENS log file directory structure. When the system processes log files or related operations, it follows symbolic links without proper validation of the target file paths. This creates a scenario where an attacker can create a symbolic link pointing to a critical system file such as an executable or configuration file that would normally require administrative privileges to modify. The operating system resolves the symbolic link and performs the intended operation on the target file, effectively bypassing normal permission checks. This type of vulnerability maps directly to CWE-639: Authorization Bypass Through User-Controlled Key and can be categorized under ATT&CK technique T1068: Exploitation for Privilege Escalation. The flaw demonstrates a failure in input validation and path resolution mechanisms, allowing attackers to exploit the trust relationship between the application and the file system.
The operational impact of this vulnerability extends beyond simple privilege escalation to potentially enable complete system compromise. An attacker who gains access to a local account can leverage this vulnerability to modify critical system files, install malicious software, or alter security configurations. The attack requires minimal privileges and can be executed through standard user accounts, making it particularly dangerous in enterprise environments where users may have elevated local access for legitimate business purposes. The vulnerability could allow attackers to modify the ENS itself, potentially disabling security protections or creating backdoors within the security infrastructure. This creates a dangerous scenario where the very security software designed to protect the system becomes a vector for compromise. The impact is compounded by the fact that ENS is widely deployed across enterprise environments, meaning that successful exploitation could affect numerous systems simultaneously.
Mitigation strategies for this vulnerability should focus on immediate software updates to the February 2020 version or later, which includes the necessary patches to address the symbolic link handling issue. Organizations should implement comprehensive monitoring of log file directories for unauthorized symbolic link creation and establish strict access controls over these locations. Network segmentation and privilege minimization should be enforced to limit the potential impact of successful exploitation attempts. Security teams should conduct thorough vulnerability assessments to identify systems running affected versions and ensure proper patch management processes are in place. Additionally, implementing file integrity monitoring solutions can help detect unauthorized modifications to critical system files that may result from exploitation of this vulnerability. Regular security awareness training should emphasize the importance of not creating symbolic links in sensitive directories and maintaining proper system access controls to prevent unauthorized privilege escalation attempts.