SB2018072408 - Multiple vulnerabilities in DENX U-Boot

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Cryptographic issues (CVE-ID: CVE-2017-3225)

The vulnerability allows a local non-authenticated attacker to gain access to sensitive information.

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.

2) Cryptographic issues (CVE-ID: CVE-2017-3226)

The vulnerability allows a local non-authenticated attacker to execute arbitrary code.

Das U-Boot is a device bootloader that can read its configuration from an AES encrypted file. Devices that make use of Das U-Boot's AES-CBC encryption feature using environment encryption (i.e., setting the configuration parameter CONFIG_ENV_AES=y) read environment variables from disk as the encrypted disk image is processed. An attacker with physical access to the device can manipulate the encrypted environment data to include a crafted two-byte sequence which triggers an error in environment variable parsing. This error condition is improperly handled by Das U-Boot, resulting in an immediate process termination with a debugging message.

Remediation

Install update from vendor's website.

References

• http://www.securityfocus.com/bid/100675
• https://www.kb.cert.org/vuls/id/166743