CVE-2021-34643 in Skaut Bazar Plugin
Summary
by MITRE • 08/16/2021
The Skaut bazar WordPress plugin is vulnerable to Reflected Cross-Site Scripting due to the use of $_SERVER['PHP_SELF'] in the ~/skaut-bazar.php file which allows attackers to inject arbitrary web scripts, in versions up to and including 1.3.2.
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Analysis
by VulDB Data Team • 08/19/2021
The CVE-2021-34643 vulnerability affects the Skaut bazar WordPress plugin, presenting a reflected cross-site scripting flaw that compromises user security. This vulnerability stems from improper input validation and output encoding practices within the plugin's codebase, specifically in the skaut-bazar.php file where the $_SERVER['PHP_SELF'] variable is utilized without adequate sanitization. The issue exists in plugin versions up to and including 1.3.2, making a significant portion of installations susceptible to exploitation.
The technical implementation of this vulnerability involves the direct use of $_SERVER['PHP_SELF'] without proper escaping or sanitization before rendering user-controllable data in web responses. This server variable contains the path of the current script, and when combined with unsanitized user input from URL parameters, creates an avenue for attackers to inject malicious scripts. The reflected nature of this XSS means that malicious code injected by an attacker is immediately reflected back to users who visit the compromised page, making exploitation straightforward and potentially widespread.
The operational impact of this vulnerability extends beyond simple script injection, as it enables attackers to perform various malicious activities including session hijacking, credential theft, and redirection to malicious sites. Attackers can craft specially formatted URLs that, when clicked by unsuspecting users, execute arbitrary JavaScript code in their browsers. This could lead to unauthorized access to user accounts, data exfiltration, or the compromise of the entire WordPress installation. The vulnerability particularly affects users who have administrative privileges or are logged into the WordPress admin interface, as the reflected scripts can potentially execute with elevated permissions.
From a cybersecurity perspective, this vulnerability aligns with CWE-79 which categorizes cross-site scripting flaws as a critical weakness in web applications. The ATT&CK framework would classify this as a technique for code injection and privilege escalation, potentially enabling attackers to move laterally within the affected environment. The vulnerability's impact is amplified by the widespread use of WordPress plugins and the typical administrative access patterns that make such exploits particularly dangerous. Organizations using the Skaut bazar plugin should immediately implement mitigations including updating to the latest version, implementing proper input validation, and applying web application firewalls to filter malicious payloads.
The remediation approach requires immediate patching of the plugin to version 1.3.3 or later, which addresses the XSS vulnerability through proper sanitization of the $_SERVER['PHP_SELF'] variable. Additionally, administrators should implement input validation measures that prevent malicious scripts from being executed in the context of the vulnerable application. Regular security audits and monitoring of plugin updates are essential to prevent similar vulnerabilities from being introduced in the future. The vulnerability demonstrates the critical importance of proper output encoding and input validation in web applications, particularly when handling server variables that may contain user-controllable data.