| Name |
Exploitation of Improperly Controlled Registers |
|
| Likelyhood of attack |
Typical severity |
| Medium |
High |
|
| Summary |
An adversary exploits missing or incorrectly configured access control within registers to read/write data that is not meant to be obtained or modified by a user. |
| Prerequisites |
Awareness of the hardware being leveraged. Access to the hardware being leveraged. |
| Solutions | Design proper access control policies for hardware register access from software and ensure these policies are implemented in accordance with the specified design. Ensure security lock bit protections are reviewed for design inconsistencies and common weaknesses. Test security lock programming flow in both pre-silicon and post-silicon environments. Leverage automated tools to test that values are not reprogrammable and that write-once fields lock on writing zeros. Ensure that measurement data is stored in registers that are read-only or otherwise have access controls that prevent modification by an untrusted agent. |
| Related Weaknesses |
|
CWE ID
|
Description
|
| CWE-1224 |
Improper Restriction of Write-Once Bit Fields |
| CWE-1231 |
Improper Implementation of Lock Protection Registers |
| CWE-1233 |
Improper Hardware Lock Protection for Security Sensitive Controls |
| CWE-1262 |
Register Interface Allows Software Access to Sensitive Data or Security Settings |
| CWE-1283 |
Mutable Attestation or Measurement Reporting Data |
|
| Related CAPECS |
|
CAPEC ID
|
Description
|
| CAPEC-1 |
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 |
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. |
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