Six U-Boot Flaws Could Enable Code Execution During Boot
Summary
Binarly disclosed six flaws in U-Boot’s FIT signature verification code: two may enable code execution during boot and four can crash devices. Upstream patches are accepted, but vendor firmware updates are still needed.
Key points
- The flaws affect U-Boot’s FIT firmware signature verification, which runs before the operating system and its security tools start.
- Two vulnerabilities could allow arbitrary code execution during firmware verification; the other four can crash the bootloader or device.
- The issues are tracked as BRLY-2026-037 through BRLY-2026-042.
- Binarly says most vulnerable code has existed since U-Boot 2013.07, potentially affecting more than 50 stable releases and downstream vendor forks.
- On systems supporting remote firmware updates, exploitation may be possible without physical access if an attacker has already compromised the management interface.
- Patches for all six flaws have been accepted upstream, but hardware vendors must incorporate them into firmware updates; unsupported devices may remain unpatched.
Article Details
- Vulnerability Types
- Memory corruption
- Out-of-bounds read
- Null pointer dereference
- Improper validation of externally stored firmware data
- Unbounded recursion
- Affected Versions
- U-Boot code dating back to version 2013.07; over 50 stable releases are potentially affected
- Exploitation Status
- unknown
- Exploit Availability
- unknown
- Patch Status
- partial