umount in util-linux 2.8 to 2.12q, 2.13-pre1, and 2.13-pre2, and other packages such as loop-aes-utils, allows local users with unmount permissions to gain privileges via the -r (remount) option, which causes the file system to be remounted with just the read-only flag, which effectively clears the nosuid, nodev, and other flags.
login in util-linux-2.12a skips pamacctmgmt and chauthtok when authentication is skipped, such as when a Kerberos krlogin session has been established, which might allow users to bypass intended access policies that would be enforced by pamacctmgmt and chauthtok.