A local overflow exists in two OpenBSD functions. The system fails to properly sanity check the semctl and semop system functions when a user-supplied semaphore set is handled. With a simple program, an attacker can cause a kernel panic and crash the system.
Denial of Service,
Loss of Integrity,
Loss of Availability
Install the 008_sem.patch provided by OpenBSD. A patch is required as there are no known workarounds.