CWE-639: Authorization Bypass Through User-Controlled Key
Description
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.
- Abstraction
- BaseA weakness specific enough to point to detection and prevention methods.
- Likelihood of exploit
- High
- Status
- Incomplete
Common consequences
- Access Control
Bypass Protection Mechanism
Access control checks for specific user data or functionality can be bypassed.
- Access Control
Gain Privileges or Assume Identity
Horizontal escalation of privilege is possible (one user can view/modify information of another user).
- Access Control
Gain Privileges or Assume Identity
Vertical escalation of privilege is possible if the user-controlled key is actually a flag that indicates administrator status, allowing the attacker to gain administrative access.
Potential mitigations
- Architecture and Design
For each and every data access, ensure that the user has sufficient privilege to access the record that is being requested.
- Architecture and DesignImplementation
Make sure that the key that is used in the lookup of a specific user's record is not controllable externally by the user or that any tampering can be detected.
- Architecture and Design
Use encryption in order to make it more difficult to guess other legitimate values of the key or associate a digital signature with the key so that the server can verify that there has been no tampering.
Related weaknesses
Parent weaknesses
CAPEC attack patterns that exploit it
CWE 4.20 links no CAPEC attack pattern to this weakness.