CVE-2019-16862 in OpenEMR
Summary
by MITRE
Reflected XSS in interface/forms/eye_mag/view.php in OpenEMR 5.x before 5.0.2.1 allows a remote attacker to execute arbitrary code in the context of a user's session via the pid parameter.
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Analysis
by VulDB Data Team • 01/17/2024
The vulnerability identified as CVE-2019-16862 represents a critical reflected cross-site scripting flaw within the OpenEMR medical records system version 5.x prior to 5.0.2.1. This security weakness exists in the specific file interface/forms/eye_mag/view.php which handles eye examination data viewing functionality. The flaw arises from insufficient input validation and output sanitization mechanisms that fail to properly escape or filter user-supplied data before incorporating it into web responses. Attackers can exploit this vulnerability by crafting malicious payloads and injecting them through the pid parameter, which is commonly used to identify patient records within the system's interface.
The technical nature of this vulnerability places it squarely within the scope of CWE-79, which defines Cross-Site Scripting (XSS) as a weakness where untrusted data is incorporated into web page content without proper sanitization. This particular implementation allows for reflected XSS attacks because the application directly reflects user input from the pid parameter back to the browser without adequate encoding or sanitization. The attack vector is particularly dangerous as it requires no privileged access or authentication, making it a remote code execution vulnerability that can be exploited by any user who can manipulate the application's URL parameters. The vulnerability specifically targets the patient identifier parameter which is fundamental to the medical records system's functionality.
The operational impact of this vulnerability extends beyond simple data theft or session hijacking. A successful exploitation could allow attackers to execute arbitrary JavaScript code within the context of a victim's browser session, potentially leading to complete compromise of the authenticated user's access to the medical records system. This could enable unauthorized viewing of sensitive patient information, modification of medical records, or even the creation of new patient entries with malicious intent. The attack could be particularly devastating in healthcare environments where the confidentiality and integrity of patient data are paramount, as it could facilitate data breaches that violate regulations such as HIPAA. The reflected nature of the attack means that victims must be tricked into clicking malicious links, but the actual exploitation occurs within their own browser session, making detection more difficult for security monitoring systems.
Mitigation strategies for CVE-2019-16862 should prioritize immediate patching of the affected OpenEMR versions to 5.0.2.1 or later, which contains the necessary input validation and output sanitization fixes. Organizations should implement comprehensive input validation at multiple layers including web application firewalls and application-level defenses to prevent malicious payloads from reaching the vulnerable code paths. The implementation of Content Security Policy headers can provide additional protection against XSS attacks by restricting the sources from which scripts can be executed. Regular security assessments and code reviews should be conducted to identify similar vulnerabilities in other components of the medical records system, particularly focusing on parameter handling and output encoding practices. Network monitoring should be enhanced to detect anomalous patterns that might indicate exploitation attempts, and user education should emphasize the importance of verifying URLs and avoiding suspicious links that could contain malicious payloads designed to exploit this vulnerability. The remediation process should also include thorough testing to ensure that the patches do not introduce regressions in the system's core functionality while maintaining the security improvements.