Weakness · Medium
CWE-1283: Mutable Attestation or Measurement Reporting Data
What it is
The register contents used for attestation or measurement reporting data to verify boot flow are modifiable by an adversary.
- Severity (our rating)
- Medium
- Likelihood of exploit
- Not rated by MITRE
- Introduced during
- Architecture and Design, Implementation
- Exploited in the wild
- No CVE in CISA's catalog
In more detail
A System-on-Chip (SoC) implements secure boot or verified boot. During this boot flow, the SoC often measures the code that it authenticates. The measurement is usually done by calculating the one-way hash of the code binary and extending it to the previous hash. The hashing algorithm should be a Secure One-Way hash function. The final hash, i.e., the value obtained after the completion of the boot flow, serves as the measurement data used in reporting or in attestation. The calculated hash is often stored in registers that can later be read by the party of interest to determine tampering of the boot flow. A common weakness is that the contents in these registers are modifiable by an adversary, thus spoofing the measurement.
What an attacker can do
- Read Memory (Confidentiality)
- Read Application Data (Confidentiality)
How to prevent it
Architecture and Design
- Measurement data should be stored in registers that are read-only or otherwise have access controls that prevent modification by an untrusted agent.
H2 Security
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Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.