Microsoft had found 5 Paragon Partition Supervisor BioNTdrv.sys driver flaws, with one utilized by ransomware gangs in zero-day assaults to achieve SYSTEM privileges in Home windows.
The weak drivers have been exploited in ‘Deliver Your Personal Weak Driver’ (BYOVD) assaults the place risk actors drop the kernel driver on a focused system to raise privileges.
“An attacker with native entry to a tool can exploit these vulnerabilities to escalate privileges or trigger a denial-of-service (DoS) situation on the sufferer’s machine,” explains a warning from CERT/CC.
“Moreover, because the assault includes a Microsoft-signed Driver, an attacker can leverage a Deliver Your Personal Weak Driver (BYOVD) method to use methods even when Paragon Partition Supervisor shouldn’t be put in. “
As BioNTdrv.sys is a kernel-level driver, risk actors can exploit vulnerabilities to execute instructions with the identical privileges as the driving force, bypassing protections and safety software program.
Microsoft researchers found all 5 flaws, noting that one in every of them, CVE-2025-0289, is leveraged in assaults by ransomware teams. Nevertheless, the researchers didn’t disclose what ransomware gangs have been exploiting the flaw as a zero-day.
“Microsoft has noticed risk actors (TAs) exploiting this weak spot in BYOVD ransomware assaults, particularly utilizing CVE-2025-0289 to realize privilege escalation to SYSTEM degree, then execute additional malicious code,” reads the CERT/CC bulletin.
“These vulnerabilities have been patched by each Paragon Software program, and weak BioNTdrv.sys variations blocked by Microsoft’s Weak Driver Blocklist.”
The Paragon Partition Supervisor flaws found by Microsoft are:
- CVE-2025-0288 – Arbitrary kernel reminiscence write brought on by the improper dealing with of the ‘memmove’ operate, permitting attackers to put in writing to kernel reminiscence and escalate privileges.
- CVE-2025-0287 – Null pointer dereference arising from a lacking validation of a ‘MasterLrp’ construction within the enter buffer, enabling the execution of arbitrary kernel code.
- CVE-2025-0286 – Arbitrary kernel reminiscence write brought on by the improper validation of user-supplied knowledge lengths, permitting attackers to execute arbitrary code.
- CVE-2025-0285 – Arbitrary kernel reminiscence mapping brought on by the failure to validate user-supplied knowledge, enabling privilege escalation by manipulating kernel reminiscence mappings.
- CVE-2025-0289 – Insecure kernel useful resource entry brought on by the failure to validate the ‘MappedSystemVa’ pointer earlier than passing it to ‘HalReturnToFirmware,’ resulting in potential compromise of system sources.
The primary 4 vulnerabilities impression Paragon Partition Supervisor variations 7.9.1 and former, whereas CVE-2025-0298, the actively exploited flaw, impacts model 17 and older.
Customers of the software program are beneficial to improve to the newest model, which comprises BioNTdrv.sys model 2.0.0, which addresses the entire talked about flaws.
Nevertheless, it is vital to notice that even customers who do not have Paragon Partition Supervisor put in are usually not secure from assaults. BYOVD ways do not depend on the software program being current on the goal’s machine.
As a substitute, risk actors embrace the weak driver with their very own instruments, permitting them to load it into Home windows and escalate privileges.
Microsoft has up to date its ‘Weak Driver Blocklist’ to dam the driving force from loading in Home windows, so customers and organizations ought to confirm the safety system is energetic.
You’ll be able to examine if the blocklist is enabled by going to Settings → Privateness & safety → Home windows Safety → Gadget safety → Core isolation → Microsoft Weak Driver Blocklist and ensuring the setting is enabled.
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Supply: BleepingComputer
A warning on Paragon Software program’s web site additionally warns that customers should improve Paragon Arduous Disk Supervisor by immediately, because it makes use of the identical driver, which shall be blocked by Microsoft immediately.
Whereas it’s unclear what ransomware gangs are exploiting the Paragon flaw, BYOVD assaults have turn out to be more and more well-liked amongst cybercriminals as they permit them to simply acquire SYSTEM privileges on Home windows gadgets.
Risk actors recognized to be using BYOVD assaults embrace Scattered Spider, Lazarus, BlackByte ransomware, LockBit ransomware, and plenty of extra.
Because of this, you will need to allow the Microsoft Weak Driver Blocklist characteristic to forestall weak drivers from getting used in your Home windows gadgets.
