CVE-2020-28938 in OpenClinic
Summary
by MITRE • 12/03/2020
OpenClinic version 0.8.2 is affected by a stored XSS vulnerability in lib/Check.php that allows users of the application to force actions on behalf of other users.
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Analysis
by VulDB Data Team • 12/12/2020
The vulnerability identified as CVE-2020-28938 affects OpenClinic version 0.8.2 and represents a critical stored cross-site scripting flaw located within the lib/Check.php component of the application. This type of vulnerability falls under the CWE-79 category, which specifically addresses cross-site scripting attacks where malicious scripts are injected into web applications and then executed when other users view the affected content. The flaw enables attackers to manipulate the application's behavior by injecting malicious code that persists in the system's database and executes whenever legitimate users access the affected pages.
The technical implementation of this vulnerability occurs through improper input validation and output encoding within the Check.php file, which processes user data without adequate sanitization mechanisms. When users submit information through the application's interface, the system fails to properly escape or validate the input before storing it in the database. This stored data is then subsequently retrieved and displayed without proper HTML escaping, creating an environment where malicious JavaScript code can be executed in the context of other users' browsers. The vulnerability specifically targets the application's authentication and authorization mechanisms, allowing attackers to perform unauthorized actions on behalf of legitimate users.
The operational impact of this stored XSS vulnerability extends beyond simple data theft or defacement, as it enables attackers to hijack user sessions and execute arbitrary commands within the application context. This capability allows malicious actors to potentially escalate privileges, access sensitive patient data, modify medical records, or even impersonate authorized users to perform administrative functions. The attack vector requires minimal user interaction since the malicious code executes automatically when other users view the affected content, making it particularly dangerous in healthcare environments where sensitive information is constantly accessed. The vulnerability's persistence through database storage means that the malicious payload remains active until manually removed from the system, creating ongoing security risks for all users who encounter the compromised data.
Security professionals should implement multiple layers of defense to mitigate this vulnerability, beginning with immediate code-level fixes that involve comprehensive input validation and output encoding throughout the application's data processing pipeline. The remediation approach should follow established secure coding practices and align with the OWASP Top Ten security principles, specifically addressing the prevention of XSS vulnerabilities through proper sanitization of user inputs. Organizations should also deploy web application firewalls to detect and block malicious payloads, implement content security policies to restrict script execution, and establish regular security testing procedures including dynamic application security testing. The mitigation strategy must include user input sanitization at multiple points in the application architecture, proper output encoding for all dynamic content, and comprehensive logging of user activities to detect potential exploitation attempts. Additionally, regular security updates and vulnerability assessments should be conducted to prevent similar issues from emerging in other components of the healthcare information system, as this vulnerability could potentially be leveraged as a stepping stone for more extensive attacks within the medical environment where patient privacy and data integrity are paramount.