OpenPanel before 2.3.0 contains a cross-site scripting vulnerability in the unauthenticated favicon proxy endpoint GET /misc/favicon that allows remote attackers to execute scripts by supplying an SVG file URL. Attackers can host malicious SVG files with embedded scripts that execute in the victim's browser on the API origin, enabling same-origin credentialed requests to authenticated endpoints.

OpenPanel versions before 2.3.0 contain a cross-site scripting (XSS) vulnerability in the unauthenticated favicon proxy endpoint GET /misc/favicon. Remote attackers can exploit this by supplying a malicious SVG file URL to the endpoint. The SVG files can contain embedded scripts that execute in the victim's browser within the API origin context. Because execution occurs on the API origin, attackers can leverage same-origin policy to make credentialed requests to authenticated endpoints. This effectively allows unauthenticated attackers to escalate privileges or exfiltrate session data by tricking users into visiting a crafted URL. The vulnerability requires no authentication to trigger, broadening the attack surface significantly. A fix is available in OpenPanel version 2.3.0 and later.