Incorrect Decoding of Security Identifiers

Opis

The product implements a decoding mechanism to decode certain bus-transaction signals to security identifiers. If the decoding is implemented incorrectly, then untrusted agents can now gain unauthorized access to the asset.

In a System-On-Chip (SoC), various integrated circuits and hardware engines generate transactions such as to access (reads/writes) assets or perform certain actions (e.g., reset, fetch, compute, etc.). Among various types of message information, a typical transaction is comprised of source identity (to identify the originator of the transaction) and a destination identity (to route the transaction to the respective entity). Sometimes the transactions are qualified with a security identifier. The security identifier helps the destination agent decide on the set of allowed actions (e.g., access an asset for read and writes). A decoder decodes the bus transactions to map security identifiers into necessary access-controls/protections.

A common weakness that can exist in this scenario is incorrect decoding because an untrusted agent's security identifier is decoded into a trusted agent's security identifier. Thus, an untrusted agent previously without access to an asset can now gain access to the asset.

Skutki

• Confidentiality, Integrity, Availability, Access Control

  Modify Memory; Read Memory; DoS: Resource Consumption (Other); Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity; Quality Degradation

Zapobieganie

• Architecture and Design

  Security identifier decoders must be reviewed for design consistency and common weaknesses.

• Implementation

  Access and programming flows must be tested in pre-silicon and post-silicon testing in order to check for this weakness.

Słabość nadrzędna

• CWE-284 Improper Access Control
• CWE-1294 Insecure Security Identifier Mechanism

Kiedy powstaje

• Implementation
• Architecture and Design

Dotyczy

Not Language-Specific, Not OS-Specific, Not Architecture-Specific, Bus/Interface Hardware, Not Technology-Specific