CWE-1334 covers designs where an unauthorized agent can inject errors into a redundant block, depriving the system of redundancy or pushing it into a degraded operating mode.
How it happens
Hardware designers add redundant blocks so that performance and reliability hold when other blocks fail. If the design lets an unauthorized agent inject errors into that redundant block, the path with injected errors can no longer serve as a backup channel.
MITRE notes the knock-on risk: the degraded mode of operation could be exploited by a later attack.
What an attacker gains
The recorded consequences are integrity and availability effects, including crash, exit or restart, instability, reduced performance and reliability, resource consumption and an unexpected state.
How to find it
The record lists no detection methods. Inventory every interface that can inject errors for test or debug, and check which modes and which agents can reach them.
How to fix it
- Do not allow error injection in modes intended for normal run-time operation.
- Put access controls on interfaces for injecting errors.
- At integration time, add an access control layer on top of any unprotected error injection interface.
Quick check
Is the redundant block itself the vulnerability?
No. The weakness is that an unauthorized agent can inject errors into it, which removes the protection it was meant to provide.
