CVE-2023-5705 in VK Filter Search Plugin
Summary
by MITRE • 10/27/2023
The VK Filter Search plugin for WordPress is vulnerable to Stored Cross-Site Scripting via the plugin's 'vk_filter_search' shortcode in all versions up to, and including, 2.3.1 due to insufficient input sanitization and output escaping on user supplied attributes. This makes it possible for authenticated attackers with contributor-level and above permissions to inject arbitrary web scripts in pages that will execute whenever a user accesses an injected page.
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Analysis
by VulDB Data Team • 04/11/2026
The VK Filter Search plugin for WordPress represents a critical security vulnerability classified as CVE-2023-5705, affecting all versions up to and including 2.3.1. This vulnerability manifests as a stored cross-site scripting flaw within the plugin's vk_filter_search shortcode implementation, creating a persistent security risk that can be exploited by authenticated attackers. The vulnerability specifically targets the plugin's handling of user-supplied attributes, where insufficient input sanitization and output escaping mechanisms fail to properly validate or sanitize data before it is processed and rendered within WordPress pages.
The technical flaw stems from inadequate data validation processes within the plugin's shortcode handling mechanism, where user-provided parameters are directly incorporated into the output without proper sanitization. This allows malicious actors to inject malicious scripts that are then stored within the WordPress database and executed whenever legitimate users access pages containing the vulnerable shortcode. The vulnerability affects authenticated users with contributor-level permissions and above, significantly expanding the potential attack surface as these roles typically have the ability to create and modify content. The stored nature of this XSS vulnerability means that the malicious scripts persist in the system and execute automatically for any user who accesses the affected pages, creating a continuous threat vector.
The operational impact of this vulnerability extends beyond simple script execution, as it can enable attackers to perform various malicious activities including session hijacking, credential theft, and data exfiltration. Attackers can leverage the stored XSS to establish persistent access to compromised WordPress installations, potentially escalating privileges or using the platform as a launchpad for further attacks against the broader network infrastructure. The vulnerability's exploitation requires minimal privileges, making it particularly dangerous as it can be leveraged by users who should normally have restricted capabilities within the WordPress environment. This creates a significant risk for WordPress sites that rely on contributor-level users for content management, as these users can inadvertently or maliciously compromise the entire system.
Security mitigation strategies for CVE-2023-5705 should prioritize immediate plugin updates to versions that address the sanitization and escaping vulnerabilities, while also implementing additional defensive measures such as input validation at multiple layers and output encoding for all user-supplied content. Organizations should consider implementing web application firewalls to detect and block malicious script injections, while also conducting thorough security audits of all installed plugins to identify similar vulnerabilities. The vulnerability aligns with CWE-79, which specifically addresses cross-site scripting flaws, and represents a clear violation of the principle of least privilege as defined in security best practices. From an ATT&CK framework perspective, this vulnerability maps to techniques involving command and control through web applications, credential access, and privilege escalation through compromised user accounts. Organizations should also consider implementing monitoring solutions to detect unusual activity patterns that might indicate exploitation attempts, while maintaining detailed logs of shortcode usage and user activities to facilitate forensic analysis if incidents occur.