CWE-1289 Detail

CWE-1289

Improper Validation of Unsafe Equivalence in Input
Incomplete
2020-02-24
00h00 +00:00
2025-12-11
00h00 +00:00
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Name: Improper Validation of Unsafe Equivalence in Input

The product receives an input value that is used as a resource identifier or other type of reference, but it does not validate or incorrectly validates that the input is equivalent to a potentially-unsafe value.

General Informations

Modes Of Introduction

Implementation

Applicable Platforms

Language

Class: Not Language-Specific (Often)

Common Consequences

Scope Impact Likelihood
OtherVaries by Context

Observed Examples

References Description

CVE-2021-39155

Chain: A microservice integration and management platform compares the hostname in the HTTP Host header in a case-sensitive way (CWE-178, CWE-1289), allowing bypass of the authorization policy (CWE-863) using a hostname with mixed case or other variations.

CVE-2020-11053

Chain: Go-based Oauth2 reverse proxy can send the authenticated user to another site at the end of the authentication flow. A redirect URL with HTML-encoded whitespace characters can bypass the validation (CWE-1289) to redirect to a malicious site (CWE-601)

CVE-2005-0269

File extension check in forum software only verifies extensions that contain all lowercase letters, which allows remote attackers to upload arbitrary files via file extensions that include uppercase letters.

CVE-2001-1238

Task Manager does not allow local users to end processes with uppercase letters named (1) winlogon.exe, (2) csrss.exe, (3) smss.exe and (4) services.exe via the Process tab which could allow local users to install Trojan horses that cannot be stopped.

CVE-2004-2214

HTTP server allows bypass of access restrictions using URIs with mixed case.

Potential Mitigations

Phases : Implementation

Vulnerability Mapping Notes

Justification : 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.
Comment : 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.

Notes

This entry is still under development and will continue to see updates and content improvements.

Submission

Name Organization Date Date release Version
CWE Content Team MITRE 2020-06-24 +00:00 2020-02-24 +00:00 4.1

Modifications

Name Organization Date Comment
CWE Content Team MITRE 2021-10-28 +00:00 updated Description
CWE Content Team MITRE 2022-10-13 +00:00 updated Observed_Examples
CWE Content Team MITRE 2023-04-27 +00:00 updated Relationships
CWE Content Team MITRE 2023-06-29 +00:00 updated Mapping_Notes
CWE Content Team MITRE 2025-12-11 +00:00 updated Weakness_Ordinalities
The information presented on CVE Find originates from several carefully selected reference sources. CVE data is provided by MITRE Corporation and the National Vulnerability Database (NVD). The Known Exploited Vulnerabilities (KEV) catalog is sourced from the Cybersecurity and Infrastructure Security Agency (CISA), while EPSS scores come from FIRST.org. Additionally, data regarding software weaknesses (CWE) and common attack patterns (CAPEC) is maintained by MITRE Corporation, and information on hardware and software configurations (CPE) is provided by the NVD.