The newEntry function in ptserver/ptprocs.c in OpenAFS before 1.6.17 allows remote authenticated users from foreign Kerberos realms to bypass intended access restrictions and create arbitrary groups as administrators by leveraging mishandling of the creator ID.
https://www.openafs.org/dl/openafs/1.6.17/RELNOTES-1.6.17
https://lists.openafs.org/pipermail/openafs-announce/2016/000496.html
http://www.openafs.org/pages/security/OPENAFS-SA-2016-001.txt
http://www.debian.org/security/2016/dsa-3569
http://git.openafs.org/?p=openafs.git%3Ba=commitdiff%3Bh=396240cf070a806b91fea81131d034e1399af1e0