CVE-2021-33562 in Shopizer
Summary
by MITRE • 05/25/2021
A reflected cross-site scripting (XSS) vulnerability in Shopizer before 2.17.0 allows remote attackers to inject arbitrary web script or HTML via the ref parameter to a page about an arbitrary product, e.g., a product/insert-product-name-here.html/ref= URL.
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Analysis
by VulDB Data Team • 05/03/2025
The vulnerability identified as CVE-2021-33562 represents a critical reflected cross-site scripting flaw within Shopizer e-commerce platform versions prior to 2.17.0. This vulnerability resides in the application's handling of URL parameters, specifically the ref parameter that is processed when users navigate to product detail pages. The flaw allows remote attackers to execute malicious scripts in the context of a victim's browser by manipulating the ref parameter in product URLs, creating a persistent vector for malicious code injection.
The technical nature of this vulnerability aligns with CWE-79, which categorizes cross-site scripting flaws as weaknesses in web applications that allow attackers to inject client-side scripts into web pages viewed by other users. In this specific case, the vulnerability manifests when the application fails to properly sanitize or encode the ref parameter before incorporating it into the HTML response. When a user visits a malformed URL such as product/insert-product-name-here.html/ref=, the application reflects the unvalidated input back to the user's browser without adequate security controls, enabling attackers to embed malicious JavaScript code within the parameter value.
The operational impact of this vulnerability extends beyond simple script execution, as it provides attackers with the capability to hijack user sessions, steal sensitive information, manipulate web content, or redirect users to malicious websites. Attackers can craft deceptive URLs that appear legitimate to users while executing unauthorized commands in their browsers. This vulnerability particularly affects e-commerce environments where user trust is paramount, as it can be exploited to compromise customer data, manipulate product information, or facilitate further attacks such as session hijacking or credential theft. The reflected nature of the vulnerability means that the attack payload is delivered through a single HTTP request and reflected back to the user, making it particularly effective for phishing attacks and social engineering campaigns.
Mitigation strategies for this vulnerability include implementing proper input validation and output encoding mechanisms to sanitize all user-supplied parameters before they are processed or displayed. Organizations should upgrade to Shopizer version 2.17.0 or later, which includes patches addressing this specific XSS vulnerability. Additional protective measures involve implementing Content Security Policy (CSP) headers to restrict script execution, employing web application firewalls to detect and block malicious requests, and conducting regular security audits of web applications to identify similar vulnerabilities. The ATT&CK framework categorizes this type of vulnerability under T1059.001 for command and scripting interpreter and T1566 for phishing techniques, highlighting the potential for attackers to leverage such vulnerabilities in broader attack chains. Security teams should also implement proper logging and monitoring to detect suspicious parameter usage patterns and ensure that all web applications undergo thorough security testing including dynamic application security testing and manual penetration testing to identify similar reflected XSS vulnerabilities across the entire application stack.