CVE-2017-3226: Das U-Boot's AES-CBC encryption feature improperly handles an error condition and may allow attacks against the underlying cryptographic implementation and allow an attacker to decrypt the data

Severity: medium (CVSS 6.4 v3.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2018-07-24 · updated 2026-06-17
Weakness: CWE-329

Description

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.

Affected products

u-boot: before 2017.09 — fixed in 2017.09

How to fix

Upgrade to a fixed version: u-boot 2017.09. Check the vendor advisory for mitigations.

References

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