Microsoft has recently discovered five vulnerabilities in the BioNTdrv.sys driver used by Paragon Partition Manager, one of which is actively exploited by ransomware gangs. These vulnerabilities were identified as part of a series of kernel driver flaws that allow attackers to escalate privileges on Windows systems. The flaw CVE-2025-0289, in particular, is being leveraged in “Bring Your Own Vulnerable Driver” (BYOVD) attacks, where attackers drop the vulnerable driver onto a targeted machine to gain SYSTEM privileges and execute further malicious actions. These attacks enable cybercriminals to bypass security protections and potentially cause denial-of-service (DoS) scenarios on the victim’s machine.
The affected vulnerabilities span several versions of Paragon Partition Manager, with four flaws impacting versions 7.9.1 and earlier, while CVE-2025-0289 affects version 17 and older.
Even if Paragon Partition Manager is not installed on a system, attackers can still exploit these vulnerabilities through the BYOVD technique by including the vulnerable driver in their own malicious tools. This method allows them to load the driver into Windows, thereby escalating privileges and bypassing system defenses.
Microsoft has responded by adding the driver to its Vulnerable Driver Blocklist, urging users to ensure that this feature is enabled for added protection.
In addition to patching the vulnerabilities, Paragon Software has recommended users upgrade to the latest version, which includes an updated version of the BioNTdrv.sys driver that addresses all of the discovered flaws. However, as the BYOVD method does not require Paragon software to be present on a machine, the risks of exploitation remain high, particularly for systems that have not enabled Microsoft’s Vulnerable Driver Blocklist. This highlights the growing popularity of BYOVD tactics among cybercriminal groups, including notorious ransomware operators like Lazarus, LockBit, and BlackByte, who are known to exploit these vulnerabilities to achieve unauthorized access and execute their malicious payloads.
Microsoft’s advisory and the update to the Vulnerable Driver Blocklist underscore the importance of proactive system defense, especially as BYOVD attacks continue to rise. Users are strongly encouraged to regularly verify that their blocklist is active and ensure their systems are protected from kernel-level exploitation. The trend of such attacks highlights the increasing sophistication of cybercriminals, who are continually evolving their methods to bypass traditional security mechanisms. With ransomware and privilege escalation attacks becoming more prevalent, staying up to date with security patches and protective measures is crucial for mitigating these high-risk threats.
