addressing [CVE-2014-0224 / CVE-2014-0221 / CVE-2014-0195 / CVE-2014-0198 / CVE-2010-5298 / CVE-2014-3470](https://www.openssl.org/news/secadv_20140605.txt) on prebuild boxes;
upgrade Chef 11.12.8-1;
upgrade VirtualBox Guest Additions 4.3.12;