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 susceptible drivers have been exploited in ‘Carry Your Personal Weak Driver’ (BYOVD) assaults the place menace 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 Carry Your Personal Weak Driver (BYOVD) approach to take advantage of techniques even when Paragon Partition Supervisor just isn’t put in. “
As BioNTdrv.sys is a kernel-level driver, menace 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 certainly one 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 menace actors (TAs) exploiting this weak point in BYOVD ransomware assaults, particularly utilizing CVE-2025-0289 to realize privilege escalation to SYSTEM stage, then execute additional malicious code,” reads the CERT/CC bulletin.
“These vulnerabilities have been patched by each Paragon Software program, and susceptible 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’ 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 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 assets.
The primary 4 vulnerabilities affect 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 really helpful to improve to the most recent model, which incorporates BioNTdrv.sys model 2.0.0, which addresses all the talked about flaws.
Nevertheless, it is vital to notice that even customers who haven’t got Paragon Partition Supervisor put in will not be protected from assaults. BYOVD ways do not depend on the software program being current on the goal’s machine.
As an alternative, menace actors embody the susceptible 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 lively.
You’ll be able to test 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 website additionally warns that customers should improve Paragon Onerous Disk Supervisor by at present, because it makes use of the identical driver, which can be blocked by Microsoft at present.
Whereas it’s unclear what ransomware gangs are exploiting the Paragon flaw, BYOVD assaults have change into more and more widespread amongst cybercriminals as they permit them to simply acquire SYSTEM privileges on Home windows gadgets.
Risk actors identified to be using BYOVD assaults embody Scattered Spider, Lazarus, BlackByte ransomware, LockBit ransomware, and plenty of extra.
For that reason, it is very important allow the Microsoft Weak Driver Blocklist function to stop susceptible drivers from getting used in your Home windows gadgets.