CVE-2019-12935 in Shopware
Summary
by MITRE
Shopware before 5.5.8 has XSS via the Query String to the backend/Login or backend/Login/load/ URI.
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Analysis
by VulDB Data Team • 10/07/2023
The vulnerability identified as CVE-2019-12935 represents a cross-site scripting flaw within the Shopware e-commerce platform affecting versions prior to 5.5.8. This security weakness resides in the backend authentication mechanism, specifically within the login endpoint and related URI paths. The flaw allows malicious actors to inject malicious scripts through the query string parameters of the backend login interface, creating a significant attack vector that could compromise the administrative backend of affected systems. The vulnerability manifests when user-supplied input from the query string is not properly sanitized or validated before being processed by the application's backend components.
The technical implementation of this vulnerability stems from insufficient input validation and output encoding practices within the Shopware framework's backend login handling code. When a user accesses the backend/login or backend/login/load/ URI paths, the application processes query string parameters without adequate sanitization measures. This allows attackers to inject malicious JavaScript code through parameters such as redirect URLs, authentication tokens, or other input fields that are processed within the login flow. The vulnerability specifically targets the query string parsing mechanism, where user-provided data is directly incorporated into the application's response without proper contextual encoding or validation. This represents a classic case of improper input handling that violates fundamental web security principles and creates opportunities for session hijacking, credential theft, and unauthorized administrative access.
The operational impact of CVE-2019-12935 extends beyond simple script injection, as it provides attackers with potential access to the entire administrative backend of affected Shopware installations. Successful exploitation could enable unauthorized users to gain administrative privileges, modify product catalogs, alter pricing structures, manipulate customer data, and potentially compromise the entire e-commerce platform. The vulnerability is particularly concerning because it affects the login mechanism itself, meaning that attackers could potentially bypass authentication entirely or manipulate the login process to redirect users to malicious sites. This type of vulnerability aligns with CWE-79, which describes cross-site scripting flaws, and represents a critical risk to web application security. The attack surface is broad as any Shopware installation running vulnerable versions could be targeted, making this a widespread concern for e-commerce businesses relying on the platform.
Organizations should implement immediate mitigations including upgrading to Shopware version 5.5.8 or later, which contains the necessary patches to address the input validation gaps. Additionally, implementing proper input sanitization measures and output encoding for all query string parameters in the backend authentication flows would provide defense-in-depth protection. Security monitoring should be enhanced to detect suspicious query string patterns and unusual login behavior that might indicate exploitation attempts. The vulnerability demonstrates the importance of following secure coding practices and proper parameter validation, particularly within authentication mechanisms where input sanitization is critical for preventing unauthorized access. This issue also highlights the necessity of regular security assessments and prompt patch management to prevent exploitation of known vulnerabilities in widely used web applications. Organizations should consider implementing web application firewalls and input validation rules that specifically target XSS attack patterns in query parameters to provide additional protection against similar vulnerabilities in the future.