Apple MacOS X SecurityServer has been reported prone to a denial of service vulnerability that may be triggered by a local user. The issue may be triggered under certain circumstances when a large password for a SecKeychainUnlock() call is specified under certain circumstances.
It has been reported that this activity will cause the SecurityServer to crash. The server appears to crash during a memory copy operation, potentially resulting in memory corruption. This could possibly allow for execution of arbitrary code, though this possibility has not been confirmed.