CWE-1191 – On-Chip Debug and Test Interface With Improper Access Control

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Description

The chip does not implement or does not correctly perform access control to check whether users are authorized to access internal registers and test modes through the physical debug/test interface.

Modes of Introduction:

– Architecture and Design

 

 

Related Weaknesses

CWE-284

 

Consequences

Confidentiality: Read Application Data

Confidentiality: Read Memory

Authorization: Execute Unauthorized Code or Commands

Integrity: Modify Memory

Integrity: Modify Application Data

Access Control: Bypass Protection Mechanism

 

Potential Mitigations

Phase: Architecture and Design

Effectiveness: High

Description: 

If feasible, the manufacturer should disable the JTAG interface or implement authentication and authorization for the JTAG interface. If authentication logic is added, it should be resistant to timing attacks. Security-sensitive data stored in registers, such as keys, etc. should be cleared when entering debug mode.

CVE References

  • CVE-2019-18827
    • chain: JTAG interface is not disabled (CWE-1191) during ROM code execution, introducing a race condition (CWE-362) to extract encryption keys