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CWE-1254 Detail

CWE-1254

Incorrect Comparison Logic Granularity
Draft
2020-02-24 00:00 +00:00
2023-10-26 00:00 +00:00
CWE Mitre.org

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Incorrect Comparison Logic Granularity

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.

Extended Description

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.

Informations

Modes Of Introduction

Architecture and Design
Implementation

Applicable Platforms

Language

Class: Not Language-Specific (Undetermined)

Operating Systems

Class: Not OS-Specific (Undetermined)

Architectures

Class: Not Architecture-Specific (Undetermined)

Technologies

Class: Not Technology-Specific (Undetermined)

Common Consequences

Scope Impact Likelihood
Confidentiality
Authorization		Bypass Protection Mechanism

Observed Examples

Reference Description
CVE-2019-10482Smartphone OS uses comparison functions that are not in constant time, allowing side channels
CVE-2019-10071Java-oriented framework compares HMAC signatures using String.equals() instead of a constant-time algorithm, causing timing discrepancies
CVE-2014-0984Password-checking function in router terminates validation of a password entry when it encounters the first incorrect character, which allows remote attackers to obtain passwords via a brute-force attack that relies on timing differences in responses to incorrect password guesses, aka a timing side-channel attack.

Potential Mitigations

Phases : Implementation

The hardware designer should ensure that comparison logic is implemented so as to compare in one operation instead in smaller chunks.


Vulnerability Mapping Notes

Rationale : This CWE entry is at the Base level of abstraction, which is a preferred level of abstraction for mapping to the root causes of vulnerabilities.
Comments : Carefully read both the name and description to ensure that this mapping is an appropriate fit. Do not try to 'force' a mapping to a lower-level Base/Variant simply to comply with this preferred level of abstraction.

Related Attack Patterns

CAPEC-ID Attack Pattern Name
CAPEC-26 Leveraging Race Conditions
The adversary targets a race condition occurring when multiple processes access and manipulate the same resource concurrently, and the outcome of the execution depends on the particular order in which the access takes place. The adversary can leverage a race condition by "running the race", modifying the resource and modifying the normal execution flow. For instance, a race condition can occur while accessing a file: the adversary can trick the system by replacing the original file with their version and cause the system to read the malicious file.

References

REF-1079

SCA4n00bz - Timing-based Sidechannel Attacks for Hardware N00bz workshop
Joe Fitzpatrick.
https://github.com/securelyfitz/SCA4n00bz

Submission

Name Organization Date Date Release Version
Arun Kanuparthi, Hareesh Khattri, Parbati Kumar Manna, Narasimha Kumar V Mangipudi Intel Corporation 2020-02-12 +00:00 2020-02-24 +00:00 4.1

Modifications

Name Organization Date Comment
CWE Content Team MITRE 2020-08-20 +00:00 updated Relationships
CWE Content Team MITRE 2021-07-20 +00:00 updated Related_Attack_Patterns
CWE Content Team MITRE 2022-10-13 +00:00 updated Demonstrative_Examples
CWE Content Team MITRE 2023-04-27 +00:00 updated Observed_Examples, Relationships
CWE Content Team MITRE 2023-06-29 +00:00 updated Mapping_Notes
CWE Content Team MITRE 2023-10-26 +00:00 updated Demonstrative_Examples, Observed_Examples

More information
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