CWE-1244

Base Abstraction Level
Pillar — Highest-level weakness category
Class — Abstract, language-independent
Base — Specific enough to detect
Variant — Tied to specific technology
Compound — Requires multiple weaknesses Stable MITRE CWE Status
Stable — Fully reviewed and complete
Draft — Under development, may change
Incomplete — Partially defined by MITRE
Deprecated — No longer recommended
Obsolete — Replaced by another CWE
Internal Asset Exposed to Unsafe Debug Access Level or State

Description

The product uses physical debug or test interfaces with support for multiple access levels, but it assigns the wrong debug access level to an internal asset, providing unintended access to the asset from untrusted debug agents.

Debug authorization can have multiple levels of access, defined such that different system internal assets are accessible based on the current authorized debug level. Other than debugger authentication (e.g., using passwords or challenges), the authorization can also be based on the system state or boot stage. For example, full system debug access might only be allowed early in boot after a system reset to ensure that previous session data is not accessible to the authenticated debugger.

Consequences

Confidentiality — Read Memory

If a protection mechanism does not ensure that internal assets have the correct debug access level during each boot stage or change in system state, an attacker could obtain sensitive information from the internal asset using a debugger.

Integrity — Modify Memory
Authorization, Access Control — Gain Privileges or Assume Identity, Bypass Protection Mechanism

Mitigations

Phase: Architecture and Design, Implementation

For security-sensitive assets accessible over debug/test interfaces, only allow trusted agents.

Phase: Architecture and Design

Apply blinding [REF-1219] or masking techniques in strategic areas.

Phase: Implementation

Add shielding or tamper-resistant protections to the device, which increases the difficulty and cost for accessing debug/test interfaces.

Detection

Manual Analysis

Check 2 devices for their passcode to authenticate access to JTAG/debugging ports. If the passcodes are missing or the same, update the design to fix and retest. Check communications over JTAG/debugging ports for encryption. If the communications are not encrypted, fix the design and retest.