Off-by-one buffer overflow in the Instance_options::complete_initialization function in instance_options.cc in the Instance Manager in MySQL before 5.0.23 and 5.1 before 5.1.12 might allow local users to cause a denial of service (application crash)

Race condition in Linux kernel 2.6.17.4 and earlier allows local users to gain root privileges by using prctl with PR_SET_DUMPABLE in a way that causes /proc/self/environ to become setuid root.