CWE-940: Improper Verification of Source of a Communication Channel

What is CWE-940?

CWE-940 is Improper Verification of Source of a Communication Channel. The flaw arises when 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. The database currently holds 29 vulnerabilities mapped to CWE-940 and none of them are in the CISA Known Exploited Vulnerabilities catalog.

OWASP TOP 10:2025 RANK7 — A07:2025 — Authentication Failures
Related CVES (365 days)29
AbstractionBase
Likelihood of exploit-

Vulnerabilities mapped to CWE-940

29 vulnerabilities314% increase year over year

No data

No vulnerability data in CISA KEV for CWE-940

Official definition

ByMitre CWE

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.

Characteristics

Modes of introduction

  • Architecture and Design
  • Implementation: REALIZATION: This weakness is caused during implementation of an architectural security tactic.

Common consequences

ImpactScopeExplanation
Gain Privileges or Assume Identity, Varies by Context, Bypass Protection MechanismAccess Control, OtherAn attacker can access any functionality that is inadvertently accessible to the source.

Risk mitigations

  1. Architecture and DesignUse 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.

Representative vulnerabilities

Below are representative vulnerabilities related to this CWE, prioritized by severity.

Sources (2)
MITRE CWE
CWE Terms of Use

Supporting documents

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