Authentication & Authorization Flaws

About

Authentication verifies who is interacting with the system. Authorization determines what that entity is allowed to do.

Flaws in either compromise core security, often without producing immediate functional errors, making them subtle yet critical from a code-quality perspective.

Authentication Flaws

Authentication flaws occur when the system fails to correctly verify identity.

Common root causes in code:

• Weak or predictable password handling

• Insecure token or session management

• Bypassing authentication checks in certain paths

• Poor multi-factor implementation

• Hardcoded credentials or secrets

Consequences:

• Unauthorized access

• Identity impersonation

• Elevated privileges when combined with other weaknesses

Conceptual insight: authentication flaws are latent correctness violations, where the code accepts entities it should not trust.

Authorization Flaws

Authorization flaws occur when permissions are misapplied, even after identity is verified.

Typical patterns:

• Missing checks on sensitive operations

• Over-permissive default roles or access levels

• Inconsistent enforcement across APIs or modules

• Hardcoded logic that does not scale with roles

Consequences:

• Privilege escalation

• Data leakage

• Critical action exposure (e.g., modifying system state without permission)

Conceptual insight: authorization flaws reflect assumption gaps in how code enforces invariants across entities.

Why They Are Hard to Detect ?

• Code may appear logically correct

• Flaws depend on combinatorial context (user, role, state, resource)

• Many checks are implicit, relying on developer discipline

• Automated analysis tools often underreport them unless patterns are clear

Connection to Code Quality

From a code-quality lens:

• Authentication/authorization logic must be centralized, explicit, and testable

• Scattered or duplicated checks increase risk of inconsistencies

• Clear invariants and defensive programming reduce latent flaws

High-quality code integrates security constraints into core logic, not as an afterthought.