In an advisory published this week, Check Point has confirmed that the flaw, tracked as CVE-2019-8461, impacts versions of the Endpoint Security Initial Client for Windows prior to E81.30, which patches the vulnerability.
In a blog post published on Tuesday, SafeBreach explained that the vulnerability impacts the Check Point Device Auxiliary Framework Service (IDAFServerHostService.exe). This service, which is executed automatically with SYSTEM privileges when the computer starts, attempts to load a library file named atl110.dll (ATL Module for Windows) from various folders listed in the PATH environment variable.
An attacker who has access to a system running Check Point Endpoint Security could place a malicious file named atl110.dll in one of these folders and it would get executed when the application starts. An attacker with administrative privileges can add their own folder to the PATH environment variable, while an attacker with more limited privileges could try to find an existing folder to which they have permission to add the malicious DLL.
By getting the Check Point software to load the malicious file with SYSTEM privileges, an attacker could escalate permissions to SYSTEM, they could use this as a persistence mechanism for their malware, or they could use it to bypass application whitelisting considering that the payload is executed by a signed service.
The vulnerability was reported to Check Point on August 1 and it was patched on August 26.
Between 2016 and 2018, researcher Stefan Kanthak identified DLL hijacking vulnerabilitiesin installers for many popular pieces of software, including cybersecurity products.