Executive brief
A critical vulnerability exists in U-Boot, a widely used bootloader for embedded devices and industrial hardware. The flaw occurs when the system processes network-based file sharing (NFS) messages, allowing a remote attacker to potentially take full control of the device before the operating system even starts. This could lead to permanent device compromise, data theft, or complete service disruption in industrial environments.
Technical details
A stack-based buffer overflow vulnerability exists in the nfs_umountall_reply helper function within the nfs_handler component of Das U-Boot. The issue stems from insufficient bounds checking when processing incoming NFS (Network File System) replies. A remote, unauthenticated attacker on the same network can exploit this by sending malicious NFS traffic to a device during its boot process. Successful exploitation can lead to arbitrary code execution with elevated privileges at the bootloader level. Siemens has identified this as affecting several RUGGEDCOM ROX II industrial devices, recommending an update to version V2.17.1 or later.
Affected products
- Das U-Boot U-Boot through 2019.07
- Siemens Corproation RUGGEDCOM ROX II family versions before V2.17.1
Timeline
- 2019-07-31: disclosed
- 2019-07-31: advisory
- 2026-05-12: other: Siemens published a downstream advisory for Ruggedcom products.