SAML messages, assertions, and metadata all commonly contain
date/time information in a standard XML format.
Invalid formatted data in such fields cause an exception of a type
that was not handled properly in the V3 software and causes a crash
(usually to the shibd daemon process, but possibly to Apache in rare
cases). Note that the crash occurs prior to evaluation of a message's
authenticity, so can be exploited by an untrusted attacker.
The problem is believed to be specific to the V3 software and would
not cause a crash in the older, now unsupported, V2 software.