In multi-threaded application, the PRNG isn't correctly reseeded in some circumstances (CVE-2013-1445)
The maintenance with bug and security fixes for UCS 3.1-x has ended on 31st of May 2014. The maintenance of the UCS 3.x major series is continued by UCS 3.2-x that is supplied with bug and security fixes. Customers still on UCS 3.1-x are encouraged to update to UCS 3.2. Please contact your partner or Univention for any questions.