Library and tools to access the BitLocker Drive Encryption (BDE) encrypted volumes - libyal/libbde
Full disk encryption is one of the cornerstones of modern endpoint protection. It is not only an effective method to protect sensitive data against physical theft, but it also protects data integrity against tampering attacks.
This blog post demonstrates how attackers can circumvent BitLocker drive encryption, how to protect against such attacks, and why acting now might pay off in the near future. The bitpixie vulnerability in Windows Boot Manager is caused by a flaw in the PXE soft reboot feature, whereby the BitLocker key is not erased from memory. To exploit this vulnerability on up-to-date systems, a downgrade attack can be performed by loading an older, unpatched boot manager. This enables attackers to extract the Volume Master Key (VMK) from main memory and bypass BitLocker encryption, which could grant them administrative access. The article also shows that privilege escalation is possible if a BitLocker PIN is set and the attacker knows the PIN. The Microsoft patch KB5025885 published in May 2023 prevents downgrade attacks on the vulnerable boot manager by replacing the old Microsoft certificate from 2011 with the new Windows UEFI CA 2023 certificate. As the old certificate will expire in 2026, this patch can also help to detect issues that may arise when the new CA will be enrolled for everyone. About bitpixie bitpixie is the nickname of a vulnerability in the Windows boot manager discovered by Rairii, which is based on a bug in the PXE soft reboot feature of the boot manager. This bug affected boot managers from 2005 to 2022; however, it can still be exploited on many updated systems using a downgrade attack. Thomas Lambertz was the first to demonstrate a complete exploitation at 38C3. He also described his implementation in a blog post. The bitpixie exploitation process is shown in the following image. A crucial component of a working exploit is the boot configuration data (BCD) file, which specifies the subsequent boot process for the Windows boot manager. As the BCD file specifies all boot media by their unique SSID, it must be crafted individually for each system to unlock the BitLocker partition. This results in a two-stage exploit process: first, a BCD file is created, an
Learn how to extract BitLocker keys from TPM 2.0 using SPI bus sniffing. A guide to reverse engineering hardware security with logic analyzers.