CWE-1318
Weakness AllowedMissing Support for Security Features in On-chip Fabrics or Buses
Abstraction: Base · Status: Incomplete
On-chip fabrics or buses either do not support or are not configured to support privilege separation or other security features, such as access control.
Dimensions
- Behavior-Property: Missing
- Behavior-Type: Support
- Other: Security Features
- Technology: Fabrics or Buses
- Other: On-chip
Mapping guidance
This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.
Modes of introduction
Certain on-chip fabrics and buses, especially simple and low-power buses, do not support security features. Apart from data transfer and addressing ports, some fabrics and buses do not have any interfaces to transfer privilege, immutable identity, or any other security attribute coming from the bus master. Similarly, they do not have dedicated signals to transport security-sensitive data from slave to master, such as completions for certain types of transactions. Few other on-chip fabrics and buses support security features and define specific interfaces/signals for transporting security attributes from master to slave or vice-versa. However, including these signals is not mandatory and could be left unconfigured when generating the register-transfer-level (RTL) description for the fabric.
Detection methods
Architecture or Design Review
Review the fabric specification and ensure that it contains signals to transfer security-sensitive signals.
Effectiveness: High
Manual Static Analysis - Source Code
Lack of security features can also be confirmed through manual RTL review of the fabric RTL.
Effectiveness: High
Content history
updated Applicable_Platforms
updated Applicable_Platforms
updated Relationships
updated Mapping_Notes
updated Weakness_Ordinalities
updated Demonstrative_Examples, Description, Dimensions, Modes_of_Introduction, Potential_Mitigations
0 vulnerabilities reference this CWE, most recent first.
No vulnerabilities reference this CWE.
Mitigation
- Such fabrics or buses should not be used to transport any security attribute coming from the bus master. In general, peripherals with security assets should not be connected to such buses before the transaction from the bus master reaches the bus, unless some form of access control is performed at a fabric bridge or another intermediate module.
- If the fabric does not support security features, implement security checks in a bridge or any component that is between the master and the fabric. Alternatively, connect all fabric slaves that do not have any security assets under one such fabric and connect peripherals with security assets to a different fabric that supports security features.
CAPEC-1: Accessing Functionality Not Properly Constrained by ACLs
In applications, particularly web applications, access to functionality is mitigated by an authorization framework. This framework maps Access Control Lists (ACLs) to elements of the application's functionality; particularly URL's for web apps. In the case that the administrator failed to specify an ACL for a particular element, an attacker may be able to access it with impunity. An attacker with the ability to access functionality not properly constrained by ACLs can obtain sensitive information and possibly compromise the entire application. Such an attacker can access resources that must be available only to users at a higher privilege level, can access management sections of the application, or can run queries for data that they otherwise not supposed to.
CAPEC-180: Exploiting Incorrectly Configured Access Control Security Levels
An attacker exploits a weakness in the configuration of access controls and is able to bypass the intended protection that these measures guard against and thereby obtain unauthorized access to the system or network. Sensitive functionality should always be protected with access controls. However configuring all but the most trivial access control systems can be very complicated and there are many opportunities for mistakes. If an attacker can learn of incorrectly configured access security settings, they may be able to exploit this in an attack.