CVE-2015-2694medium
Description
The kdcpreauth modules in MIT Kerberos 5 (aka krb5) 1.12.x and 1.13.x before 1.13.2 do not properly track whether a client's request has been validated, which allows remote attackers to bypass an intended preauthentication requirement by providing (1) zero bytes of data or (2) an arbitrary realm name, related to plugins/preauth/otp/main.c and plugins/preauth/pkinit/pkinit_srv.c.
References
http://krbdev.mit.edu/rt/Ticket/Display.html?id=8160
http://www.oracle.com/technetwork/topics/security/linuxbulletinoct2015-2719645.html
http://www.securityfocus.com/bid/74824
http://www.ubuntu.com/usn/USN-2810-1
https://github.com/krb5/krb5/commit/e3b5a5e5267818c97750b266df50b6a3d4649604