resteasy XXE vulnerability
by Wang Veronica
Hi experts,
We use resteasy 3.0.6final, and XXE vulnerability was reported during penetration test.
Seems that 3.0.6final contains partial fix for XXE vulnerability, but need to set resteasy.document.expand.entity.references parameter to false explicitly. A more complete fix seems to have been done after 3.0.10.
We can upgrade to a more recent version, e.g. 3.1.2. Another option I am thinking is not to support XML Media type (we actually need to support json only). Is this a feasible approach to ultimately avoid XXE attack and any pointers to achieve this? (In our REST API code, we currently declare consume and produce annotations to support application/xml and application/json).
Is there a simple resteasy configuration to disable support of application/xml?
Thanks, Veronica
8 months, 2 weeks
Selecting MessageBodyWriter seems to ignore priority given a specific type match
by Steven Schlansker
Hi Resteasy users, [ apologies for the re-post, sent from wrong email the first time ]
I'm a happy user of Resteasy + Jackson for Json processing.
Recently, I had the misfortune of attempting to serialize a basic String:
client.post(Entity.json("Test"));
if you call Jackson directly, it does the right thing:
mapper.writeValueAsString("Test") => "\"Test\""
However, much to my surprise, when sending it via JAX-RS client, it is written as a bare word without quotes -- and is rejected server-side.
After some debugging, I realized that both StringTextStar and JacksonJsonProvider were ending up with Priorities.USER and being seen as equivalent.
No good! So I changed my registration:
context.register(new JacksonJsonProvider(myMapper), Integer.MAX_VALUE);
I then proceeded to triumphantly ... observe the same test failure as before!
Dug quite a bit further in, and it seems that the selection process in MediaTypeMap$TypedEntryComparator
has the unfortunate property that it will select (via compareTypes) a *less priority* MessageBodyWriter if the type is a tighter bound on the Entity.
So in my case, I get
StringTextStar -> String.class@5000
JacksonJsonProvider -> Object.class(a)Integer.MAX_VALUE
and the TypedEntryComparator selects StringTextStar since String is-assignable to Object, despite my attempt at an ultimate priority registration.
How do I fix this? Preferably without removing StringTextStar entirely, as I'm sure that will break something else (reading error messages perhaps).
Thanks for any advice,
Steven
8 months, 2 weeks
