BaseIncomplete

CWE-939Improper Authorization in Handler for Custom URL Scheme

Category: auth

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.

Common consequences· 1

  • Access Control / Other — 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· 1

  • [Architecture and Design]

References

  1. https://cwe.mitre.org/data/definitions/939.html

(incoming)2

TypeTargetConfidenceTier
VulnerabilityCVE-2026-33335cve-2026-333350%live
VulnerabilityCVE-2026-35394cve-2026-353940%live

Related by meaning· 6

Nearest entities by semantic similarity across the cs-graph corpus.

CWE
Insufficiently Protected Credentials
CWE
Improper Access Control
CWE
Exposure of Sensitive Information to an Unauthorized Actor
CWE
External Control of Critical State Data
CWE
Weak Authentication
CWE
Use of Implicit Intent for Sensitive Communication
Sourced from MITRE CWE 4.20. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.