Open redirect vulnerability in gluon/tools.py in Web2py 2.9.11 allows remote attackers to redirect users to arbitrary web sites and conduct phishing attacks via a URL in the _next parameter to user/logout.Referenceshttps://github.com/web2py/web2py/commit/e31a099cb3456fef471886339653430ae59056b0https://github.com/web2py/web2py/issues/731
