CVE-2022-41099

FAQ

What kind of security feature could be bypassed by successfully exploiting this vulnerability?

A successful attacker could bypass the BitLocker Device Encryption feature on the system storage device. An attacker with physical access to the target could exploit this vulnerability to gain access to encrypted data.

Are there additional steps that I need to take to be protected from this vulnerability?

Yes. You must apply the applicable Windows security update to your Windows Recovery Environment (WinRE). For more information about how to apply the WinRE update, see Add an update package to Windows RE.

IMPORTANT: End users and enterprises who are updating Windows devices which are already deployed in their environment can instead use the latest Windows Safe OS Dynamic Updates to update WinRE when the partition is too small to install the full Windows update. You can download the latest Windows Safe OS Dynamic Update from the Microsoft Update Catalog.

Can a bootable Windows ISO or USB flash drive that boot to Windows RE be used to exploit this vulnerability?

No. The exploit is only possible with the winre.wim on the recovery partition of the device.

Can a vulnerable version of WinRE WIM file be used to exploit this vulnerability?

No. A BitLocker encrypted drive cannot be accessed via an arbitrary WinRE WIM file hosted on an external drive. Please complete all steps in [Microsoft Learn | Add an Update to Windows RE | Apply the update to a running PC to ensure that the updated Windows RE image is turned on and correctly configured for your Windows installation.

If TPM+PIN BitLocker protectors are being used, can the vulnerability be exploited if the attacker does not know the TPM PIN?

No. To exploit the vulnerability the attacker needs to know the TPM PIN if the user is protected by the BitLocker TPM+PIN.

Is there a way I can automate the process of updating WinRE on my Windows devices which have already been deployed?

Yes. Microsoft has developed a sample script that can help you automate updating WinRE from the running Windows OS. Please see KB5025175: Updating the WinRE partition on deployed devices to address security vulnerabilities in CVE-2022-41099 for more information.