CWE · MITRE source

CWE-939Improper Authorization in Handler for Custom URL Scheme

Abstraction: Base · CVEs in our corpus: 27

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.

Last updated: 22 August 2026 14:14 UTC