Policy Uses Obsolete Encoding

Opis

The product uses an obsolete encoding mechanism to implement access controls.

Within a System-On-a-Chip (SoC), various circuits and hardware engines generate transactions for the purpose of accessing (read/write) assets or performing various actions (e.g., reset, fetch, compute, etc.). Among various types of message information, a typical transaction is comprised of source identity (identifying the originator of the transaction) and a destination identity (routing the transaction to the respective entity). Sometimes the transactions are qualified with a Security Token. This Security Token helps the destination agent decide on the set of allowed actions (e.g., access to an asset for reads and writes). A policy encoder is used to map the bus transactions to Security Tokens that in turn are used as access-controls/protection mechanisms. A common weakness involves using an encoding which is no longer trusted, i.e., an obsolete encoding.

Skutki

• Confidentiality, Integrity, Availability, Access Control

  Modify Memory; Read Memory; Modify Files or Directories; Read Files or Directories; DoS: Resource Consumption (Other); Execute Unauthorized Code or Commands; Gain Privileges or Assume Identity; Bypass Protection Mechanism; Reduce Reliability

Zapobieganie

• Architecture and Design, Implementation

  Security Token Decoders should be reviewed for design inconsistency and common weaknesses.

  Access and programming flows should be tested in both pre-silicon and post-silicon testing.

  Skuteczność: High

Słabość nadrzędna

• CWE-284 Improper Access Control

Kiedy powstaje

• Architecture and Design
• Implementation

Dotyczy

Not Language-Specific, Not OS-Specific, Not Architecture-Specific, Not Technology-Specific

Źródła

1. Huge Intel CPU Bug Allegedly Causes Kernel Memory Vulnerability With Up To 30% Performance Hit In Windows And Linux — Brandon Hill, 2018