CVE-2018-8711 in Products Filter Plugin
Summary
by MITRE
A local file inclusion issue was discovered in the WooCommerce Products Filter (aka WOOF) plugin before 2.2.0 for WordPress, as demonstrated by the shortcode parameter in a woof_redraw_woof action. The vulnerability is due to the lack of args/input validation on render_html before allowing it to be called by extract(), a PHP built-in function. Because of this, the supplied args/input can be used to overwrite the $pagepath variable, which then could lead to a local file inclusion attack.
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Analysis
by VulDB Data Team • 02/05/2021
The vulnerability identified as CVE-2018-8711 represents a critical local file inclusion flaw within the WooCommerce Products Filter plugin, specifically affecting versions prior to 2.2.0. This issue resides within the WordPress ecosystem and demonstrates how inadequate input validation can lead to severe security implications. The vulnerability manifests through the shortcode parameter within the woof_redraw_woof action, creating an attack vector that allows malicious actors to manipulate the plugin's behavior through crafted input parameters. The root cause of this vulnerability stems from insufficient sanitization of user-supplied data before it is processed by the plugin's internal functions.
The technical implementation of this vulnerability exploits a fundamental flaw in how the plugin handles parameter validation and variable assignment. When the plugin processes the shortcode parameter, it fails to properly validate or sanitize the input before passing it to the extract() function, which is a PHP built-in that imports variables from an array into the current symbol table. This lack of proper input validation creates a scenario where attackers can manipulate the $pagepath variable through the supplied arguments, effectively allowing them to control which files are included locally on the server. The vulnerability is classified as a CWE-22 - Improper Limitation of a Pathname to a Restricted Directory, which specifically addresses the issue of inadequate path validation that can lead to unauthorized file access.
The operational impact of this vulnerability extends beyond simple data exposure, as it provides attackers with the capability to execute arbitrary code on the affected WordPress server. When an attacker successfully exploits this vulnerability, they can potentially include and execute malicious files stored on the server, leading to complete system compromise. The attack surface is particularly concerning because it targets a widely used plugin within the WordPress ecosystem, making numerous websites vulnerable to exploitation. This vulnerability can be leveraged to perform various malicious activities including data theft, privilege escalation, and establishment of persistent backdoors within the compromised systems. The implications are further amplified by the fact that WooCommerce is one of the most popular e-commerce platforms, meaning that exploitation could lead to significant financial losses and data breaches.
Mitigation strategies for CVE-2018-8711 should prioritize immediate plugin updates to version 2.2.0 or later, which includes proper input validation and sanitization measures. Organizations should implement comprehensive security monitoring to detect potential exploitation attempts and maintain up-to-date security patches for all WordPress components. Additional protective measures include implementing web application firewalls to filter suspicious input patterns, conducting regular security audits of installed plugins, and establishing robust access controls to limit the potential impact of successful exploitation. The vulnerability also highlights the importance of following secure coding practices such as input validation, output encoding, and principle of least privilege in web application development. From an ATT&CK framework perspective, this vulnerability aligns with techniques involving command and control communication and privilege escalation, emphasizing the need for layered defensive measures including network segmentation and continuous monitoring to prevent unauthorized access and maintain system integrity.