MISP contains a cross-site scripting (XSS) vulnerability in the TAXII object viewer. When displaying a remote TAXII object, the JSON content of string properties was rendered directly into an HTML pre block without HTML-encoding. An attacker who can control or influence the content of a TAXII object (e.g., by publishing a malicious object to a TAXII server that the victim's MISP instance subscribes to) can inject arbitrary HTML or JavaScript that executes in the context of the victim's MISP session.
Preconditions:
Impact:
-
Execution of arbitrary JavaScript in the victim's browser within the MISP application context.
-
Potential theft of session tokens, API keys, or other sensitive data accessible from the MISP interface.
-
Potential for performing actions on behalf of the authenticated user.
Affected versions: <2.5.48.
The fix applies HTML-encoding (via the h() helper) to the JSON string before it is interpolated into the HTML pre element. This ensures that any HTML or script markup present in the JSON string properties of a TAXII object is rendered as inert text rather than being parsed and executed by the browser, eliminating the XSS vector.