CVE-2020-5729 in OpenMRS
Summary
by MITRE
In OpenMRS 2.9 and prior, the UI Framework Error Page reflects arbitrary, user-supplied input back to the browser, which can result in XSS. Any page that is able to trigger a UI Framework Error is susceptible to this issue.
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Analysis
by VulDB Data Team • 05/06/2025
The vulnerability identified as CVE-2020-5729 represents a critical cross-site scripting weakness within the OpenMRS platform version 2.9 and earlier. This security flaw resides in the UI Framework Error Page component which fails to properly sanitize user-supplied input before rendering it in the browser context. The vulnerability stems from the application's failure to implement adequate input validation and output encoding mechanisms when processing error conditions, creating an avenue for malicious actors to inject arbitrary script code that executes in the context of authenticated users' browsers.
The technical implementation of this vulnerability occurs through the UI Framework's error handling mechanism where error messages containing unescaped user input are directly rendered back to the browser without proper sanitization. When any page within the OpenMRS application triggers a UI Framework Error condition, the system reflects the user-supplied data back to the browser without appropriate encoding or filtering. This design flaw allows attackers to craft malicious input that, when processed through the error handling path, gets executed as JavaScript code within the victim's browser session. The vulnerability is particularly concerning because it affects any page capable of triggering a UI Framework Error, making it broadly exploitable across the entire application surface.
The operational impact of this vulnerability extends beyond simple data theft or session hijacking. An attacker who successfully exploits this XSS flaw can execute arbitrary code in the context of authenticated users' browsers, potentially leading to complete system compromise. The attack vector requires minimal privileges as the vulnerability exists in the error handling mechanism that is invoked during normal application operation. This means that even routine user activities could trigger the vulnerability, making it particularly dangerous in healthcare environments where OpenMRS systems handle sensitive patient data. The reflected nature of the XSS allows for immediate execution without requiring persistent storage of malicious payloads, enabling attackers to perform actions such as stealing session cookies, modifying application behavior, or redirecting users to malicious sites.
Mitigation strategies for this vulnerability should focus on implementing comprehensive input validation and output encoding mechanisms throughout the UI Framework. The recommended approach involves sanitizing all user-supplied input before it reaches any error handling components and ensuring that all error messages are properly encoded before being rendered in the browser. This aligns with CWE-79 which categorizes cross-site scripting vulnerabilities and follows the defensive programming principles outlined in the OWASP Top Ten. Organizations should also implement Content Security Policy headers to add an additional layer of protection against script execution. The most effective long-term solution involves upgrading to OpenMRS versions that have addressed this vulnerability through proper input sanitization and output encoding implementations, as specified in the ATT&CK framework's technique T1059 for command and scripting interpreter execution. Regular security audits and input validation testing should be implemented to prevent similar vulnerabilities from emerging in other components of the healthcare information system.