CVE-2020-15479: 
PassMark PerformanceTest vulnerability analysis and mitigation

An issue was discovered in PassMark BurnInTest through 9.1, OSForensics through 7.1, and PerformanceTest through 10. The vulnerability (CVE-2020-15479) was discovered in the DirectIo32.sys and DirectIo64.sys kernel drivers distributed with these applications. The vulnerability was discovered and reported by Michal Poslušný in June 2020, and was fixed in the August 2020 updates (ESET Research).

When the driver receives an IOCTL request from a user-mode program, it attempts to copy the request input buffer into a local buffer on the stack. The vulnerability occurs because the size of the memcpy operation is based solely on the size of the input buffer and does not consider the capacity of the stack buffer. This oversight can lead to a buffer overflow when a sufficiently large IOCTL buffer is provided. The issue exists in multiple locations within the IOCTL handler function, and several IOCTLs can be used to trigger this vulnerability (ESET Research, NVD).

The vulnerability is rated as high severity as it could lead to arbitrary Ring-0 code execution and escalation of privileges, potentially allowing attackers to gain complete control over the affected system (ESET Research).

The exploitability is rated as Medium/Low. The driver must be loaded prior to exploitation to be utilized by low-privilege users. If the driver is not already loaded, the attacker would require administrative rights for driver installation (ESET Research).

The vulnerability was addressed in the August 2020 updates of the vendor's products. Users should update to the latest versions of BurnInTest, OSForensics, and PerformanceTest to receive the fixed version of the driver (ESET Research).