CWE-1254β€”Incorrect Comparison Logic Granularity

PUBLISHEDweakness record
released 2020-02-24 Β· last modified 2025-12-11

Metadata

CWE ID:
CWE-1254
Abstraction:
Base
Structure:
Simple
Status:
Draft
Release Date:
2020-02-24
Latest Modification Date:
2025-12-11

Weakness Name

Incorrect Comparison Logic Granularity

Description

The product's comparison logic is performed over a series of steps rather than across the entire string in one operation. If there is a comparison logic failure on one of these steps, the operation may be vulnerable to a timing attack that can result in the interception of the process for nefarious purposes.

Comparison logic is used to compare a variety of objects including passwords, Message Authentication Codes (MACs), and responses to verification challenges. When comparison logic is implemented at a finer granularity (e.g., byte-by-byte comparison) and breaks in the case of a comparison failure, an attacker can exploit this implementation to identify when exactly the failure occurred. With multiple attempts, the attacker may be able to guesses the correct password/response to challenge and elevate their privileges.

Common Consequences

Scope:
Confidentiality, Authorization
Impact:
Bypass Protection Mechanism

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