Executive brief
barebox, an open-source bootloader used in embedded systems, is vulnerable to a flaw in how it processes network configuration requests. An attacker on the same local network can send a specially crafted network packet that causes the system to crash during the startup process. This could lead to a denial-of-service, preventing the device from booting or operating correctly.
Technical details
An out-of-bounds read vulnerability exists in the dhcp_message_type() function of the barebox bootloader. The issue stems from a failure to verify that the options pointer remains within the bounds of the received packet during DHCP option parsing. Specifically, if a crafted DHCP Offer or ACK packet is received without a proper 0xff end marker, the parser may read past the valid packet data. This can be exploited by an unauthenticated attacker on the same broadcast domain to cause a denial-of-service (system crash). The vulnerability is addressed in version 2026.04.0.
Affected products
- barebox barebox prior to 2026.04.0
Timeline
- 2026-04-17: patched: Version 2026.04.0 released
- 2026-05-11: advisory: CVE-2026-34960 published