wsse:Security: MustUnderstand headers are not understood

[Frizz]

I have a Consumer that sends messages with Security enabled, so something
like this:

<soap:Envelope xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/";>
    <soap:Header>
    ...
        <wsse:Security xmlns:wsse="
http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-secext-1.0.xsd";
xmlns:wsu="
http://docs.oasis-open.org/wss/2004/01/oasis-200401-wss-wssecurity-utility-1.0.xsd";
soap:mustUnderstand="1">
            ...
        </wsse:Security>
    </soap:Header>
    ...
</soap:Envelope>


My Provider has NO Security enabled, but I'd like to process those messages
anyway (please don't ask why ;-)

Of course I get a "MustUnderstand headers are not understood" exeption.

Setting mustUnderstand="0" in the Consumer code would solve this problem -
but is not an option.

Question:
- Can I "patch" this mustUnderstand from 1 to 0 using an Interceptor on the
Provider side?
- Could I use a dummy handler that marks ALL headers as 'understood'? How
would I do this?