Das U-Boot is a device bootloader that can read its configuration from an AES encrypted file. For devices utilizing this environment encryption mode, U-Boot's use of a zero initialization vector may allow attacks against the underlying cryptographic implementation and allow an attacker to decrypt the data. Das U-Boot's AES-CBC encryption feature uses a zero (0) initialization vector. This allows an attacker to perform dictionary attacks on encrypted data produced by Das U-Boot to learn information about the encrypted data.