CWE-603

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 Draft 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
Use of Client-Side Authentication

Description

A client/server product performs authentication within client code but not in server code, allowing server-side authentication to be bypassed via a modified client that omits the authentication check.

Client-side authentication is extremely weak and may be breached easily. Any attacker may read the source code and reverse-engineer the authentication mechanism to access parts of the application which would otherwise be protected.

Consequences

Access Control — Bypass Protection Mechanism, Gain Privileges or Assume Identity

Mitigations

Phase: Architecture and Design

Do not rely on client side data. Always perform server side authentication.