Re: CVE-Request: Assign CVE for common-collections remote code execution on deserialisation flaw

[Mark Felder <feld () feld me>]

On Fri, Nov 13, 2015, at 01:58, Gsunde Orangen wrote:
> I share Tim's view [2] and a dozen of (own) applications we checked
> won't break. A property that re-enables deserialization of course would
> help additionally: allow applications that really *need* this to get it
> working; but that requires an explicit step - so latest by that time:
> those, whose applications break after including a "fixed" version of
> Commons-Collections would (hopefully) start to think about their design.
>
> Gsunde
>
> [1] http://seclists.org/oss-sec/2015/q4/238
> [2] http://seclists.org/oss-sec/2015/q4/263

This statement is how we have been operating our mitigation strategy:

"Applications which use Apache Commons Collections and do not use
deserialization are not vulnerable."

Assuming that statement is correct, disabling deserialization by default
doesn't offer additional protection to people. Instead it requires a
code change when they upgrade to re-enable it and cause them to be
vulnerable again.

Would the greater community be better served by additional documentation
on how to safely handle the deserialization in their application? Is
there such a method, or is this hopelessly broken?

If you're still vulnerable even if you don't use deserialization in your
application this completely changes our risk profile and we need to
change our mitigation strategy.


-- 
  Mark Felder
  feld () feld me