CWE-939: Improper Authorization in Handler for Custom URL Scheme
Description
The product uses a handler for a custom URL scheme, but it does not properly restrict which actors can invoke the handler using the scheme.
Mobile platforms and other architectures allow the use of custom URL schemes to facilitate communication between applications. In the case of iOS, this is the only method to do inter-application communication. The implementation is at the developer's discretion which may open security flaws in the application. An example could be potentially dangerous functionality such as modifying files through a custom URL scheme.
- Abstraction
- BaseA weakness specific enough to point to detection and prevention methods.
- Likelihood of exploit
- Not rated by MITRE
- Status
- Incomplete
Common consequences
- Access ControlOther
Gain Privileges or Assume Identity; Varies by Context; Bypass Protection Mechanism
An attacker can access any functionality that is inadvertently accessible to the source.
Potential mitigations
- Architecture and Design
Utilize a user prompt pop-up to authorize potentially harmful actions such as those modifying data or dealing with sensitive information. When designing functionality of actions in the URL scheme, consider whether the action should be accessible to all mobile applications, or if an allowlist of applications to interface with is appropriate.
Related weaknesses
CAPEC attack patterns that exploit it
CWE 4.20 links no CAPEC attack pattern to this weakness.