CVE-2017-14722 in WordPress
Summary
by MITRE
Before version 4.8.2, WordPress allowed a Directory Traversal attack in the Customizer component via a crafted theme filename.
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Analysis
by VulDB Data Team • 01/14/2021
The vulnerability identified as CVE-2017-14722 represents a critical directory traversal flaw within WordPress's Customizer component that existed prior to version 4.8.2. This security weakness stems from inadequate input validation mechanisms that fail to properly sanitize theme filenames submitted through the customizer interface. The flaw allows attackers to manipulate file paths and potentially access restricted directories on the web server, creating a significant vector for unauthorized data access and system compromise.
The technical implementation of this vulnerability resides in the way WordPress processes theme filenames within the Customizer functionality. When users interact with the customizer interface to preview themes, the system accepts user-supplied filename parameters without sufficient sanitization or validation. This creates an opportunity for malicious actors to craft specially formatted filenames that exploit path traversal sequences such as ../ or ..\ to navigate beyond the intended theme directory. The vulnerability specifically affects the theme preview mechanism where WordPress attempts to load theme files for visualization purposes, but fails to properly validate the file paths against the intended directory boundaries.
From an operational perspective, this vulnerability poses severe risks to WordPress installations as it enables attackers to potentially access sensitive files including configuration files, database credentials, and other system resources that should remain protected. The directory traversal attack can be leveraged to read arbitrary files from the server filesystem, potentially exposing authentication tokens, user data, or system configuration details. This weakness can be particularly dangerous in environments where WordPress is used for content management, e-commerce, or other applications handling sensitive information, as it could lead to complete system compromise and data breaches.
The impact of this vulnerability aligns with CWE-22, which categorizes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal. This weakness allows attackers to access files and directories that are outside the intended scope, often leading to unauthorized information disclosure or system compromise. The vulnerability also maps to ATT&CK technique T1083, which covers discovery of file and directory permissions, as attackers can leverage this flaw to enumerate system files and understand the underlying filesystem structure. Organizations using vulnerable WordPress installations face significant risk of data exposure, system integrity compromise, and potential regulatory violations if sensitive information is accessed through this vector.
The recommended mitigation strategy involves immediate upgrading to WordPress version 4.8.2 or later, which includes proper input validation and sanitization of theme filenames within the Customizer component. Additionally, administrators should implement proper network segmentation, monitor for unusual file access patterns, and ensure that the web server has minimal permissions to prevent escalation of privileges. Regular security audits of WordPress installations, including plugin and theme verification, should be conducted to identify and remediate similar vulnerabilities. Organizations should also consider implementing web application firewalls and intrusion detection systems to monitor for exploitation attempts targeting this specific vulnerability pattern.