MISP TAXII Object Viewer Stored XSS via Unescaped JSON Output

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:

- The victim must be an authenticated MISP user with access to the TAXII object viewer.

- The victim must open or view the crafted TAXII object.

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.