The inode_init_owner function in fs/inode.c in the Linux kernel through 3.16 allows local users to create files with an unintended group ownership, in a scenario where a directory is SGID to a certain group and is writable by a user who is not a member of that group. Here, the non-member can trigger creation of a plain file whose group ownership is that group. The intended behavior was that the non-member can trigger creation of a directory (but not a plain file) whose group ownership is that group. The non-member can escalate privileges by making the plain file executable and SGID.

Under certain conditions, on F5 BIG-IP 13.0.0-13.1.0.5, 12.1.0-12.1.3.1, or 11.6.1 HF2-11.6.3.1, virtual servers configured with Client SSL or Server SSL profiles which make use of network hardware security module (HSM) functionality are exposed and impacted by this issue.