CVE-2019-3965 in OpenEMR
Summary
by MITRE
In OpenEMR 5.0.1 and earlier, controller.php contains a reflected XSS vulnerability in the document_id parameter. This could allow an attacker to execute arbitrary code in the context of a user's session.
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Analysis
by VulDB Data Team • 11/27/2023
The vulnerability identified as CVE-2019-3965 affects OpenEMR version 5.0.1 and earlier, representing a critical reflected cross-site scripting flaw within the controller.php script. This weakness specifically manifests through the document_id parameter, which fails to properly sanitize user input before incorporating it into web responses. The vulnerability resides in the application's failure to implement adequate input validation and output encoding mechanisms, creating an attack surface where malicious payloads can be injected and subsequently executed within user browsers. The reflected nature of this vulnerability means that the malicious script is reflected off the web server to the victim's browser, typically through crafted URLs that contain the malicious payload.
The technical exploitation of this vulnerability follows standard XSS attack patterns where an attacker crafts a malicious URL containing JavaScript code within the document_id parameter. When a victim clicks such a link, the malicious script executes within the victim's browser session, potentially allowing the attacker to hijack the user's session, steal sensitive information, or perform unauthorized actions on behalf of the user. This flaw directly maps to CWE-79, which describes cross-site scripting vulnerabilities where untrusted data is improperly handled and reflected back to users without proper sanitization or encoding. The vulnerability represents a significant risk to healthcare organizations utilizing OpenEMR, as it could enable attackers to access patient records, manipulate medical data, or execute arbitrary commands within the application context.
From an operational perspective, the impact of CVE-2019-3965 extends beyond simple script execution to encompass potential data breaches and system compromise within healthcare environments. The vulnerability's presence in a medical records system creates opportunities for attackers to gain unauthorized access to sensitive patient information, violating healthcare privacy regulations such as HIPAA. The reflected nature of the attack means that exploitation typically requires social engineering to convince victims to click malicious links, but once executed, the consequences can be severe including complete session hijacking, data exfiltration, and potential lateral movement within the network. This vulnerability also aligns with ATT&CK technique T1566, which covers social engineering tactics involving spearphishing with links, making it particularly dangerous in healthcare environments where users may trust links from seemingly legitimate sources.
Organizations should implement immediate mitigations including updating to OpenEMR versions 5.0.2 or later where this vulnerability has been patched, applying proper input validation and output encoding to all parameters, and implementing content security policies to prevent unauthorized script execution. The patch addresses the core issue by ensuring that the document_id parameter undergoes proper sanitization before being processed or returned in web responses. Additionally, security teams should conduct thorough penetration testing to identify similar vulnerabilities in other application components and implement comprehensive web application firewalls to detect and block malicious payloads. Regular security awareness training for healthcare staff becomes essential to prevent successful social engineering attacks that exploit this vulnerability, as the human element remains the primary attack vector for reflected XSS exploitation in healthcare environments.