OpenEMR through 8.2.0 contains a stored cross-site scripting vulnerability in the patient portal template system that allows authenticated administrators to inject arbitrary HTML and JavaScript by storing malicious payloads through the template save mode, which only filters literal PHP open tags. Attackers can exploit the lack of output encoding at the template retrieval endpoint combined with missing HttpOnly cookie attributes to exfiltrate session tokens via document.cookie access, enabling full session hijacking of any admin, clinician, or portal patient who views a poisoned template.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
High
Admin privileges needed
User Interaction
Passive
Minimal interaction
Impact Assessment
Confidentiality
None
No data leak
Integrity
None
No data modification
Availability
None
No disruption
CVSS Vector v4.0