CVE-2017-18356 in WooCommerce plugin
Summary
by MITRE
In the Automattic WooCommerce plugin before 3.2.4 for WordPress, an attack is possible after gaining access to the target site with a user account that has at least Shop manager privileges. The attacker then constructs a specifically crafted string that will turn into a PHP object injection involving the includes/shortcodes/class-wc-shortcode-products.php WC_Shortcode_Products::get_products() use of cached queries within shortcodes.
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Analysis
by VulDB Data Team • 10/17/2024
The vulnerability CVE-2017-18356 represents a critical php object injection flaw within the Automattic WooCommerce plugin for WordPress, affecting versions prior to 3.2.4. This vulnerability operates under the premise that an attacker must first compromise a legitimate user account with at least Shop Manager privileges, which grants sufficient access to manipulate the plugin's functionality. The attack vector specifically targets the shortcode implementation within the WooCommerce ecosystem, particularly focusing on the WC_Shortcode_Products::get_products() method located in includes/shortcodes/class-wc-shortcode-products.php. The flaw manifests when the plugin processes cached queries through shortcodes, creating a pathway for malicious code execution.
The technical implementation of this vulnerability stems from improper handling of user-supplied data within the shortcode processing pipeline. When a Shop Manager or higher-privileged user accesses the WordPress admin interface and triggers a specific shortcode with crafted parameters, the plugin's internal caching mechanism becomes vulnerable to manipulation. The cached queries in the WC_Shortcode_Products::get_products() function do not adequately sanitize or validate input parameters, allowing attackers to inject serialized PHP objects that can be deserialized during subsequent processing. This object injection occurs because the plugin fails to properly escape or validate serialized data structures that are passed through shortcode attributes, creating a direct path for remote code execution.
The operational impact of CVE-2017-18356 extends beyond simple privilege escalation, as it enables attackers to execute arbitrary code on compromised WordPress installations with the full privileges of the compromised user account. The vulnerability is particularly dangerous in environments where Shop Manager accounts have elevated permissions, as these users often possess access to critical administrative functions including product management, order processing, and plugin configuration. The attack requires minimal network interaction and can be executed through standard WordPress shortcode functionality, making it accessible to attackers with basic knowledge of WordPress plugin exploitation techniques. This vulnerability aligns with CWE-502, which describes "Deserialization of Untrusted Data" as a fundamental weakness in software design that allows attackers to manipulate serialized objects.
Security professionals should consider this vulnerability in the context of the MITRE ATT&CK framework, particularly under the techniques related to privilege escalation and code execution within web applications. The attack chain typically involves initial access through compromised credentials, followed by exploitation of the shortcode functionality to achieve remote code execution. Organizations should implement robust input validation and sanitization measures, particularly for user-supplied shortcode parameters. The recommended mitigation strategy involves upgrading to WooCommerce version 3.2.4 or later, which includes proper sanitization of input parameters and enhanced validation of serialized data within the shortcode processing pipeline. Additionally, network segmentation and monitoring of WordPress admin activities can help detect anomalous shortcode usage patterns that may indicate exploitation attempts. The vulnerability demonstrates the critical importance of validating all user inputs and implementing proper object serialization security measures in web applications, as highlighted by industry best practices and security standards such as those outlined in OWASP Top Ten and NIST cybersecurity frameworks.