Incorrect Chaining or Granularity of Debug Components
This vulnerability occurs when hardware debug components, such as test ports and scan chains, are incorrectly connected or organized within a chip's design. This misconfiguration can create unintended access paths, potentially exposing sensitive internal data or functions.
Modern chips incorporate specialized debug components like Test Access Ports (TAPs) for boundary scans, internal scan cells for stimulus/response testing, and custom tracing hubs for monitoring. If these elements are chained together incorrectly or organized with improper granularity during the design phase, it breaks the intended security model of the debug infrastructure. This design or synthesis error creates hidden backdoors or elevates access permissions within the chip. Attackers could exploit these flawed connections to bypass security controls, extract cryptographic keys, or manipulate the chip's internal state, turning vital debugging features into serious security liabilities.
Impact: Gain Privileges or Assume IdentityBypass Protection MechanismExecute Unauthorized Code or CommandsModify MemoryModify Files or Directories
Depending on the access to debug component(s) erroneously granted, an attacker could use the debug component to gain additional understanding about the system to further an attack and/or execute other commands. This could compromise any security property, including the ones listed above.