VMware Carbon Black’s Threat Analysis Unit (TAU) has identified dozens of previously unknown vulnerable kernel drivers that could be exploited by attackers to alter firmware or escalate privileges.
It’s not uncommon for threat actors, including cybercriminals and state-sponsored groups, to abuse kernel drivers in their operations. Such drivers can allow malicious hackers to manipulate system processes, maintain persistence on a system, and evade security products.
VMware’s TAU collected roughly 18,000 Windows driver samples from VirusTotal using a Yara rule. After excluding drivers that were already known to be vulnerable, the researchers identified a few hundred file hashes associated with 34 unique, previously unknown vulnerable drivers.
The analysis targeted both Windows Driver Model (WDM) and Windows Driver Framework (WDF) drivers, and the company has published a list of the file names associated with the problematic drivers. Some of the drivers belong to major BIOS, PC and chip makers.
Each of these drivers can allow attackers with non-system privileges to gain full control of the targeted device.
“By exploiting the vulnerable drivers, an attacker without the system privilege may erase/alter firmware, and/or elevate privileges,” VMware said in a blog post describing its research.
The developers of the vulnerable drivers were notified in the spring of 2023, but VMware said only two of them fixed the vulnerabilities, namely Phoenix Technologies and Advanced Micro Devices.
VMware has developed proof-of-concept (PoC) exploits for several of the vulnerable drivers, to show how they can be exploited to erase firmware or for privilege escalation.
The company has also made available an IDAPython script that it used to automate the hunt for vulnerable WDM and WDF drivers.