2148
Common Consequences
Scope Impact Likelihood
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
High
Potential Mitigations
Phase: Architecture and Design
Security identifier decoders must be reviewed for design inconsistency and common
weaknesses.
Phase: Implementation
Access and programming flows must be tested in pre-silicon and post-silicon testing.
Demonstrative Examples
Example 1:
Consider a system that supports AHB. Let us assume we have a follower agent that only
understands OCP. To connect this follower to the leader, a bridge is introduced, i.e., AHB to OCP.
The follower has assets to protect accesses from untrusted leaders, and it employs access
controls based on policy, (e.g., AES-Key registers for encryption or decryption). The key is 128
bits implemented as a set of four 32-bit registers. The key registers are assets, and register
AES_KEY_ACCESS_POLICY is defined to provide the necessary access controls.
The AES_KEY_ACCESS_POLICY access-policy register defines which agents with a
security identifier in the transaction can access the AES-key registers. The implemented
AES_KEY_ACCESS_POLICY has 4 bits where each bit when "Set" allows access to the AES-Key
registers to the corresponding agent that has the security identifier. The other bits from 31 through
4 are reserved and not used.
During conversion of the AHB-to-OCP transaction, the security identifier information must be
preserved and passed on to the follower correctly.
Example Language: Other (Bad)
In AHB-to-OCP bridge, the security identifier information conversion is done incorrectly.
Because of the incorrect conversion, the security identifier information is either lost or could be
modified in such a way that an untrusted leader can access the AES-Key registers.
Example Language: Other (Good)
The conversion of the signals from one protocol (AHB) to another (OCP) must be done while preserving the security
identifier correctly.
MemberOf Relationships
This MemberOf relationships table shows additional CWE Catgeories and Views that reference this
weakness as a member. This information is often useful in understanding where a weakness fits
within the context of external information sources.
Nature Type ID Name Page
MemberOf 1396 Comprehensive Categorization: Access Control 1400 2519
CWE Version 4.14
CWE-1293: Missing Source Correlation of Multiple Independent Data
CWE-1293: Missing Source Correlation of Multiple Independent Data