CVE-2021-43141 in Simple Subscription Website
Summary
by MITRE • 11/03/2021
Cross Site Scripting (XSS) vulnerability exists in Sourcecodester Simple Subscription Website 1.0 via the id parameter in plan_application.
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Analysis
by VulDB Data Team • 02/24/2025
The CVE-2021-43141 vulnerability represents a critical cross site scripting flaw within the Sourcecodester Simple Subscription Website version 1.0, specifically manifesting through the id parameter in the plan_application component. This vulnerability falls under the CWE-79 category of Cross Site Scripting, which is one of the most prevalent and dangerous web application security flaws. The vulnerability allows attackers to inject malicious scripts into web pages viewed by other users, potentially leading to session hijacking, data theft, or unauthorized actions performed on behalf of victims. The affected application appears to be a subscription management system that likely handles user plans and billing information, making it an attractive target for cybercriminals seeking to exploit user trust.
The technical exploitation of this vulnerability occurs when the application fails to properly sanitize or validate user input through the id parameter in the plan_application module. When users navigate to pages that utilize this parameter without adequate input filtering, malicious scripts can be executed in the context of other users' browsers. This type of vulnerability typically arises from improper output encoding or insufficient input validation mechanisms within the web application's codebase. The attack vector is particularly concerning because it can be triggered through simple parameter manipulation, requiring minimal technical expertise to exploit. The vulnerability demonstrates a fundamental weakness in the application's data handling processes where user-supplied data is directly incorporated into dynamic web content without proper security controls.
From an operational perspective, this XSS vulnerability poses significant risks to both the application's integrity and user security. Attackers could potentially steal user sessions, redirect victims to malicious websites, or even modify subscription details and billing information. The impact extends beyond individual user accounts to potentially compromise the entire subscription management system, affecting business operations and customer trust. Organizations utilizing this software would face potential regulatory compliance issues, especially if customer data is compromised or if the vulnerability leads to unauthorized financial transactions. The vulnerability could also enable attackers to perform privilege escalation attacks if the application's access controls are not properly implemented, potentially allowing unauthorized users to gain administrative privileges.
Mitigation strategies for CVE-2021-43141 should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application. The primary defense involves sanitizing all user inputs, particularly parameters like id, before they are processed or displayed in web pages. This includes implementing proper HTML escaping and context-appropriate encoding for dynamic content. Organizations should also consider implementing Content Security Policy (CSP) headers to limit script execution and prevent unauthorized code injection. Additionally, regular security code reviews and automated vulnerability scanning should be integrated into the development lifecycle to identify similar issues before they can be exploited. The remediation process must include updating the affected software to a patched version if available, as recommended by the vendor. This vulnerability highlights the importance of adhering to secure coding practices and following OWASP Top Ten guidelines for preventing XSS attacks, particularly in web applications that handle sensitive user information and financial transactions.