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Hi,
by chance we found a problem that can create a security risk. The scenario is a CXF WS consumer endpoint configured without WSDL and right after that a step, e.g. a setHeader that uses an XPath to access the CXF payload. When you now create a http GET request on the endpoint (normally it should be POST) then the error No type converter available to convert from type: org.apache.camel.component.cxf.converter.CachedCxfPayload to the required type: javax.xml.transform.sax.SAXSource with value org.apache.camel.component.cxf.converter.CachedCxfPayload@45812dad
is thrown.
First of all it is surprising that CXF accepts the request. Second a type conversion like that is possible. The reason for this error message is within the type converter coding. The converter returns a null object for the not existing payload of the GET request but this is interpreted as there is no type converter available. One could say that this is just a bad error message but more over the type converter is now kind of black-listed internally. That means the next calls being correct or wrong will not look for a type converter but return immedeately the above error. That means the endpoint is blocked until the scenario is restarted. This seems to be more efficient than a DOS attack (but of course one has to have access rights). I provide a simple patch that raises a runtime exception in the CXF type converter when there is no payload. I am not 100% sure whether this is the best way to fix it. Maybe GET requests should be blocked already in CXF. I also could imagine that somethin like that is also possible in other components.
We use Camel 2.16.2 and I tested it in CXF 2.16.3 and it is not fixed.