Update to version 1.6.3

Shibboleth SP software vulnerable to forged user attribute data

The Service Provider software relies on a generic XML parser to process
SAML responses and there are limitations in older versions of the parser
that make it impossible to fully disable Document Type Definition (DTD)
processing.

Through addition/manipulation of a DTD, it's possible to make changes
to an XML document that do not break a digital signature but are
mishandled by the SP and its libraries. These manipulations can alter
the user data passed through to applications behind the SP and result
in impersonation attacks and exposure of protected information.

While the use of XML Encryption can serve as a mitigation for this bug,
it may still be possible to construct attacks in such cases, and the SP
does not provide a means to enforce its use.

An updated version of XMLTooling-C (V1.6.3) is available that works
around this specific bug.

While newer versions of the parser are configured by the SP into
disallowing the use of a DTD via an environment variable, this feature
is not present in the parser used on some supported platforms (notably
Red Hat and CentOS 7), so an additional fix is being provided now that
an actual DTD exploit has been identified.

Security: CVE-2018-0486