CVE-2021-31327 in Remote Clinic
Summary
by MITRE • 04/22/2021
Stored XSS in Remote Clinic v2.0 in /medicines due to Medicine Name Field.
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Analysis
by VulDB Data Team • 05/03/2025
The vulnerability identified as CVE-2021-31327 represents a critical stored cross-site scripting flaw within the Remote Clinic v2.0 web application, specifically manifesting in the medicines management module. This vulnerability arises from inadequate input validation and sanitization mechanisms applied to the Medicine Name field, creating a persistent security weakness that allows attackers to inject malicious script code into the application's database. The affected component resides in the /medicines endpoint, where user-provided medicine names are stored without proper sanitization, enabling the execution of malicious scripts when legitimate users view the stored data.
The technical exploitation of this vulnerability follows a standard stored XSS attack pattern where malicious input is first submitted through the Medicine Name field and subsequently stored in the application's backend database. When other users navigate to pages displaying these stored medicine names, the malicious scripts execute within their browser context, potentially leading to session hijacking, credential theft, or redirection to malicious sites. This flaw directly maps to CWE-79 which defines cross-site scripting as the failure to properly sanitize user input, and aligns with ATT&CK technique T1531 which describes the use of malicious inputs to compromise application security. The vulnerability demonstrates a classic insecure data handling pattern where user-supplied data flows directly into the application's output without proper context-aware sanitization or encoding.
The operational impact of CVE-2021-31327 extends beyond simple script execution, potentially enabling attackers to escalate privileges and access sensitive patient medical information stored within the Remote Clinic application. Given that this is a healthcare application, the consequences could include unauthorized access to patient records, medical history, and treatment details, violating privacy regulations such as HIPAA. The stored nature of this vulnerability means that malicious scripts persist indefinitely until manually removed from the database, creating a long-term security risk. Attackers could leverage this vulnerability to establish persistent backdoors, harvest session cookies from authenticated users, or redirect users to phishing sites designed to capture login credentials. The attack surface is particularly concerning in healthcare environments where applications often contain highly sensitive data and where attackers may have access to multiple systems through a single compromised entry point.
Mitigation strategies for this vulnerability should prioritize immediate input sanitization and output encoding measures within the Remote Clinic application. The implementation of proper input validation should include character set restrictions, length limitations, and the removal of potentially dangerous characters such as angle brackets, script tags, and javascript protocols. The application should employ context-aware output encoding when displaying stored medicine names, ensuring that any potentially malicious content is rendered harmless through proper HTML entity encoding. Security patches should be deployed immediately to address the root cause, including the implementation of a comprehensive sanitization framework that validates all user inputs before storage. Additionally, the application should implement Content Security Policy headers to limit script execution and prevent unauthorized code injection. Regular security assessments should be conducted to identify similar vulnerabilities in other application components, with input validation mechanisms being applied consistently across all user-facing data entry points. The remediation process should also include user education about the importance of avoiding suspicious inputs and monitoring for unusual application behavior that might indicate exploitation attempts.