CVE-2021-38348 in Advance Search Plugin
Summary
by MITRE • 09/10/2021
The Advance Search WordPress plugin is vulnerable to Reflected Cross-Site Scripting via the wpas_id parameter found in the ~/inc/admin/views/html-advance-search-admin-options.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 1.1.2.
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Analysis
by VulDB Data Team • 09/16/2021
The vulnerability identified as CVE-2021-38348 affects the Advance Search WordPress plugin, specifically targeting versions up to and including 1.1.2. This represents a critical security flaw that exposes WordPress installations to reflected cross-site scripting attacks, which fall under the CWE-79 category of Cross-Site Scripting. The vulnerability manifests through the wpas_id parameter within the html-advance-search-admin-options.php file, which serves as an administrative interface component for the plugin's advanced search functionality. Attackers can exploit this weakness by crafting malicious URLs that contain script code within the wpas_id parameter, leading to the execution of unauthorized scripts in the context of authenticated admin sessions.
The technical implementation of this vulnerability stems from inadequate input validation and output sanitization within the plugin's administrative interface. When the wpas_id parameter is processed without proper sanitization, the malicious payload gets reflected back to the user's browser without appropriate encoding or escaping mechanisms. This allows attackers to inject HTML and JavaScript code that executes in the browser of any user who visits the specially crafted URL. The reflected nature of this vulnerability means that the malicious script is not stored on the server but is instead injected through the request parameters, making it particularly dangerous for administrative interfaces where privileged users might inadvertently click on malicious links.
The operational impact of this vulnerability extends beyond simple script injection, as it provides attackers with potential access to administrative functions and sensitive data within the WordPress environment. An attacker who successfully exploits this vulnerability could execute arbitrary code with the privileges of the authenticated administrator, potentially leading to complete system compromise. This risk is particularly severe because the vulnerability exists within an administrative interface component, meaning that successful exploitation could allow attackers to modify plugin settings, access sensitive configuration data, or even modify content within the WordPress installation. The vulnerability creates a pathway for attackers to escalate privileges and gain unauthorized access to critical system resources.
Mitigation strategies for this vulnerability should focus on immediate patching of the affected plugin to version 1.1.3 or later, which contains the necessary security fixes. Organizations should also implement input validation measures at the web application firewall level to filter out potentially malicious payloads in URL parameters. Additionally, administrators should ensure that only authorized personnel have access to administrative interfaces and consider implementing multi-factor authentication to reduce the risk of unauthorized access. The vulnerability aligns with ATT&CK technique T1059.007 for script injection and T1548.001 for privilege escalation, highlighting the need for comprehensive security measures beyond simple patch management. Regular security audits and monitoring of administrative interface access patterns can help detect potential exploitation attempts and provide early warning of compromise.