CWE-940

Base Abstraction Level
Pillar — Highest-level weakness category
Class — Abstract, language-independent
Base — Specific enough to detect
Variant — Tied to specific technology
Compound — Requires multiple weaknesses Incomplete MITRE CWE Status
Stable — Fully reviewed and complete
Draft — Under development, may change
Incomplete — Partially defined by MITRE
Deprecated — No longer recommended
Obsolete — Replaced by another CWE
Improper Verification of Source of a Communication Channel

Description

The product establishes a communication channel to handle an incoming request that has been initiated by an actor, but it does not properly verify that the request is coming from the expected origin.

When an attacker can successfully establish a communication channel from an untrusted origin, the attacker may be able to gain privileges and access unexpected functionality.

Top Monitored CVEs

CVE-2025-61932
CRITICAL KEV
9.8 2.7%
2025-10-20

Consequences

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.

Mitigations

Phase: Architecture and Design

Use a mechanism that can validate the identity of the source, such as a certificate, and validate the integrity of data to ensure that it cannot be modified in transit using an Adversary-in-the-Middle (AITM) attack. 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.