CVE-2020-35272 in Employee Performance Evaluation System
Summary
by MITRE • 01/20/2021
Employee Performance Evaluation System in PHP/MySQLi with Source Code 1.0 is affected by cross-site scripting (XSS) in the Admin Portal in the Task and Description fields.
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Analysis
by VulDB Data Team • 02/18/2021
The Employee Performance Evaluation System version 1.0 represents a web-based application built using php and mysqli technologies that facilitates administrative tasks including employee performance tracking and evaluation processes. This system includes an admin portal designed for authorized personnel to manage various aspects of employee performance data, with functionality covering task assignment and description management. The vulnerability exists within this administrative interface where user input is not properly sanitized or validated before being rendered back to users, creating a pathway for malicious actors to inject harmful scripts.
The technical flaw manifests as a cross-site scripting vulnerability specifically within the Task and Description fields of the admin portal. When administrators or users input data containing script tags or malicious code into these fields, the application fails to implement proper input sanitization measures. The system processes this unvalidated data without adequate encoding or filtering mechanisms, allowing the malicious scripts to execute in the context of other users' browsers who view the affected content. This vulnerability falls under the CWE-79 category of Cross-Site Scripting, specifically targeting the administrative interface where sensitive operations occur. The flaw represents a classic reflected XSS vulnerability where user-supplied data flows directly into the application's output without proper context-dependent encoding.
The operational impact of this vulnerability extends beyond simple data corruption or display issues, as it provides attackers with potential access to administrative functions and sensitive employee data. An attacker could craft malicious payloads that, when executed in an administrator's browser, might redirect them to phishing sites, steal session cookies, or execute unauthorized actions within the application. The vulnerability is particularly concerning because it affects the admin portal, which typically has elevated privileges and access to confidential employee information. This creates opportunities for privilege escalation attacks where attackers could potentially gain unauthorized access to employee records, modify performance data, or manipulate the evaluation system itself. The vulnerability also aligns with ATT&CK technique T1566 for initial access through malicious content and T1071 for application layer protocol usage.
Mitigation strategies should focus on implementing comprehensive input validation and output encoding mechanisms throughout the application. The system must employ proper sanitization techniques such as HTML entity encoding for all user-supplied data before rendering it in the browser context. Implementing Content Security Policy headers can provide additional protection against script execution, while strict input validation should filter out or escape potentially dangerous characters and script tags. The application should utilize prepared statements for all database interactions to prevent injection attacks, and implement proper session management with secure cookie attributes. Regular security testing including automated scanning and manual penetration testing should be conducted to identify similar vulnerabilities throughout the application codebase, with security patches applied promptly when issues are discovered. The system should also implement proper access controls and audit logging to detect unauthorized access attempts and maintain accountability for administrative actions.