Linux distributions using CAP_SYS_NICE for gnome-shell may be exposed to a privilege escalation issue. An attacker, with low privilege permissions, may take advantage of the way CAP_SYS_NICE is currently implemented and eventually load code to increase its process scheduler priority leading to possible DoS of other services running in the same machine.
Weakness
The product attempts to drop privileges but does not check or incorrectly checks to see if the drop succeeded.
Affected Software
| Name |
Vendor |
Start Version |
End Version |
| Gnome-shell |
Gnome |
- (including) |
- (including) |
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