Oracle Solaris tags many user binaries to enable address space layout randomization (ASLR). ASLR randomizes the starting address of key parts of an address space. This security defense mechanism can cause Return Oriented Programming (ROP) attacks to fail when they try to exploit software vulnerabilities. Zones inherit this randomized layout for their processes. Because the use of ASLR might not be optimal for all binaries, ASLR is configurable at the zone and binary level.