CWE-1429 is a hardware interface that silently discards operations in situations where feedback would matter for security, such as timely detection of failures or attacks.
It touches silicon designers and firmware and driver authors, and anyone who builds on a root of trust.
How it happens
Some systems withhold feedback on purpose. MITRE gives the example of encryption algorithms that always return ciphertext regardless of errors, so attackers learn nothing about internal state. That can be a legitimate security measure, but it must be tightly controlled, or it hides operational failures that need prompt attention.
Without confirmation that an operation ran, failures go undetected. The record's observed example is an open source silicon root of trust product that did not report right away when an integrity check failed for memory requests, so it accepted and kept processing data.
What an attacker gains
- Confidentiality. Critical data may be exposed when operations are silently dropped.
- Integrity. Operations may proceed on wrong assumptions, causing corruption or incorrect behavior.
- Availability. Unhandled discarded operations can exhaust resources and cause crashes or denial of service, and administrators lack the signal to respond.
How to find it
MITRE lists automated static analysis of source for missing error handling or feedback (rated high for catching common issues early) and manual source review by experts for unhandled operations (moderate, useful for design level omissions).
How to fix it
- Design in logging and feedback for discarded operations from the start. Rated high, since addressing it at design time stops it from appearing later.
- Check at implementation that every critical operation has logging or error feedback. Rated moderate, complementing the design measures.
Quick check
Is withholding feedback ever acceptable?
Sometimes, as a deliberate security policy, but MITRE says it must be strictly controlled so it does not hide failures that need detection.
