CVE-2020-25502

Vulnerability

A DLL hijacking vulnerability exists in the Cybereason Defense Platform (EDR) for versions 19.1.282 and above, 19.2.182 and above, 20.1.343 and above, and 20.2.X and above [2]. The flaw occurs when the application loads a dynamically linked library without properly validating the search path or authenticating the DLL file, enabling a local user to place a malicious DLL in a directory that the application searches before the system directory [1] [2].

Exploitation

An attacker must have local access to the endpoint with low privileges. By placing a specially crafted DLL in a specific directory that the Cybereason EDR process searches (e.g., a user-writable folder on the path), the attacker can force the service to load the malicious DLL instead of the legitimate one [1]. The attack does not require network access or user interaction beyond the initial compromise of the local system [2].

Impact

Successful exploitation allows the attacker to execute arbitrary code in the context of the Cybereason EDR service, which typically runs with SYSTEM or high-integrity privileges [2]. This results in local privilege escalation, enabling the attacker to gain full control over the affected endpoint, including the ability to disable security software, access sensitive data, or move laterally within the network [2].

Mitigation

Cybereason has remediated this vulnerability in all supported sensor versions: 19.1.282 and above, 19.2.182 and above, 20.1.343 and above, and 20.2.X and above [2]. Affected users should update to the latest version of the Cybereason Defense Platform. No workaround is needed if the product is kept up-to-date [2]. The vulnerability was disclosed in July 2020, and the fix was validated by Cybereason's security team [2].