CVE-2020-10107 in Daily Expense Tracker System
Summary
by MITRE
PHPGurukul Daily Expense Tracker System 1.0 is vulnerable to stored XSS, as demonstrated by the ExpenseItem or ExpenseCost parameter in manage-expense.php.
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Analysis
by VulDB Data Team • 03/06/2020
The PHPGurukul Daily Expense Tracker System version 1.0 contains a critical stored cross-site scripting vulnerability that affects the application's user input validation mechanisms. This vulnerability exists within the manage-expense.php script where the ExpenseItem and ExpenseCost parameters fail to properly sanitize user-provided data before storing it in the application's database. The flaw allows attackers to inject malicious javascript code that persists in the system and executes whenever other users view the affected expense records.
This stored XSS vulnerability represents a significant security risk as it enables attackers to execute arbitrary javascript code within the context of other users' browsers. The vulnerability is classified under CWE-79 as a failure to sanitize user input, specifically manifesting as cross-site scripting in the web application. The attack vector is particularly dangerous because it operates through the application's legitimate data storage and retrieval mechanisms, making it difficult to detect and prevent through traditional network-based security measures.
The operational impact of this vulnerability extends beyond simple data theft or session hijacking. Attackers can leverage this flaw to perform session manipulation, redirect users to malicious websites, steal sensitive information, or even escalate privileges within the application. The persistent nature of stored XSS means that malicious code remains active until manually removed from the database, potentially affecting multiple users over extended periods. This vulnerability directly violates security principles outlined in the OWASP Top Ten 2017, specifically targeting the A03:2017 - Injection category, where improper input validation leads to unauthorized code execution.
The exploitation of this vulnerability follows the typical ATT&CK framework pattern for web application attacks, beginning with reconnaissance to identify the vulnerable parameters, followed by payload delivery through the ExpenseItem and ExpenseCost fields. Once executed, the malicious javascript can access the victim's session cookies, redirect them to attacker-controlled domains, or perform actions on behalf of the authenticated user. The vulnerability affects the application's integrity and confidentiality, as it allows unauthorized modification of the application's behavior and potential data exfiltration. Organizations using this system should immediately implement input sanitization measures, implement proper output encoding, and conduct comprehensive security testing to identify similar vulnerabilities in other application components.
Mitigation strategies should include implementing proper input validation and sanitization for all user-provided parameters, deploying web application firewalls to detect and block malicious payloads, and conducting regular security audits of the application's codebase. The fix should involve escaping special characters in user input before database storage and implementing Content Security Policy headers to prevent unauthorized script execution. Additionally, the application should be updated to the latest version where this vulnerability has been patched, and security awareness training should be provided to developers to prevent similar issues in future code development cycles.