Microsoft had found 5 Paragon Partition Supervisor BioNTdrv.sys driver flaws, with one utilized by ransomware gangs in zero-day assaults to realize SYSTEM privileges in Home windows.
The weak drivers have been exploited in ‘Carry 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) state of affairs on the sufferer’s machine,” explains a warning from CERT/CC.
“Moreover, because the assault entails a Microsoft-signed Driver, an attacker can leverage a Carry Your Personal Weak Driver (BYOVD) method to take advantage of programs 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 motive force, bypassing protections and safety software program.
Microsoft researchers found all 5 flaws, noting that one in all them, CVE-2025-0289, is leveraged in assaults by ransomware teams. Nonetheless, 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 attributable to the improper dealing with of the ‘memmove’ perform, 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 attributable to the improper validation of user-supplied knowledge lengths, permitting attackers to execute arbitrary code.
- CVE-2025-0285 – Arbitrary kernel reminiscence mapping attributable to the failure to validate user-supplied knowledge, enabling privilege escalation by manipulating kernel reminiscence mappings.
- CVE-2025-0289 – Insecure kernel useful resource entry attributable to the failure to validate the ‘MappedSystemVa’ pointer earlier than passing it to ‘HalReturnToFirmware,’ resulting in potential compromise of system assets.
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 advisable to improve to the newest model, which comprises BioNTdrv.sys model 2.0.0, which addresses all the talked about flaws.
Nonetheless, it is necessary to notice that even customers who haven’t got Paragon Partition Supervisor put in are usually not secure from assaults. BYOVD techniques do not depend on the software program being current on the goal’s machine.
As an alternative, 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 motive force from loading in Home windows, so customers and organizations ought to confirm the safety system is energetic.
You’ll be able to test if the blocklist is enabled by going to Settings → Privateness & safety → Home windows Safety → Machine 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 Exhausting Disk Supervisor by at the moment, because it makes use of the identical driver, which shall be blocked by Microsoft at the moment.
Whereas it’s unclear what ransomware gangs are exploiting the Paragon flaw, BYOVD assaults have turn out to be more and more standard amongst cybercriminals as they permit them to simply achieve SYSTEM privileges on Home windows units.
Risk actors recognized to be using BYOVD assaults embrace Scattered Spider, Lazarus, BlackByte ransomware, LockBit ransomware, and plenty of extra.
For that reason, you will need to allow the Microsoft Weak Driver Blocklist function to forestall weak drivers from getting used in your Home windows units.
