utils/mount.ecryptfs_private.c in ecryptfs-utils before 90 does not properly check mountpoint permissions, which allows local users to effectively replace any directory with a new filesystem, and consequently gain privileges, via a mount system call.

ecryptfs-utils: suid helper does not restrict mounting filesystems with nosuid,nodev which creates a possible privilege escalation

mount.ecryptfs_private.c in eCryptfs-utils does not validate mount destination filesystem types, which allows local users to gain privileges by mounting over a nonstandard filesystem, as demonstrated by /proc/$pid.