CVE-2021-24840 in Squaretype Theme
Summary
by MITRE • 11/08/2021
The Squaretype WordPress theme before 3.0.4 allows unauthenticated users to manipulate the query_vars used to retrieve the posts to display in one of its REST endpoint, without any validation. As a result, private and scheduled posts could be retrieved via a crafted request.
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Analysis
by VulDB Data Team • 11/11/2021
The vulnerability identified as CVE-2021-24840 affects the Squaretype WordPress theme version 3.0.3 and earlier, representing a critical access control flaw that undermines the security of content retrieval mechanisms. This issue resides within the theme's REST API endpoint implementation where query parameters are processed without proper validation, creating a pathway for unauthorized information disclosure. The vulnerability specifically targets the query_vars parameter handling within the theme's REST endpoints, which are designed to control how posts are fetched and displayed on WordPress sites. Attackers can exploit this weakness by crafting malicious requests that manipulate the query parameters to bypass normal access controls and retrieve content that should remain restricted.
The technical flaw stems from insufficient input validation and sanitization within the theme's REST endpoint code. When unauthenticated users submit requests to the affected endpoints, the system fails to properly validate or sanitize the query_vars parameter, allowing attackers to inject custom parameters that modify the database query logic. This lack of validation creates a direct path for retrieving private posts, scheduled posts, and potentially other restricted content that would normally be inaccessible to users without proper authentication or authorization. The vulnerability is classified as a weakness in input validation according to CWE-20, which specifically addresses improper validation of input data that can lead to unauthorized access and information disclosure.
The operational impact of this vulnerability is significant as it enables attackers to bypass WordPress's inherent content access controls without requiring any authentication credentials. This means that malicious actors can systematically enumerate and retrieve private blog posts, scheduled content, drafts, and other sensitive information that should only be accessible to authorized users. The implications extend beyond simple information disclosure, as private content often contains confidential business information, unreleased product details, internal communications, or other proprietary data that could be exploited for competitive advantage or further attack vectors. The vulnerability essentially undermines the fundamental security model of WordPress content management systems where access control is enforced through authentication and role-based permissions.
Organizations using affected versions of the Squaretype theme should immediately implement mitigations including updating to version 3.0.4 or later, which contains the necessary patches to validate and sanitize query parameters in REST endpoints. Additionally, administrators should review their site's REST API access controls and implement proper rate limiting to prevent automated enumeration attacks. The vulnerability aligns with ATT&CK technique T1213.002 which involves data from information repositories, specifically targeting WordPress REST API endpoints for unauthorized data access. Security monitoring should be enhanced to detect unusual patterns in REST API requests that might indicate exploitation attempts, particularly those involving query parameter manipulation. Network segmentation and firewall rules can also be implemented to restrict access to REST endpoints from untrusted networks, providing an additional layer of defense against this type of information disclosure attack.