A write protection lock bit was left unset after boot on an older generation of Lenovo and IBM System x servers, potentially allowing an attacker with administrator access to modify the subset of flash memory containing Intel Server Platform Services (SPS) and the system Flash Descriptors.
Weakness
During installation, installed file permissions are set to allow anyone to modify those files.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Flex_system_x240_m4_firmware |
Lenovo |
* |
a3e122b (excluding) |
Potential Mitigations
- Compartmentalize the system to have “safe” areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
- Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
References