Apparatus and methods for preventing denial of service attacks

In one aspect of the invention, the frames of a thread stack that associated with the misbehaving code are popped from the thread stack. Exception handling code is allowed to execute for trusted code by popping the trusted code frame via processing an exception, but exception handling is not allowed to execute for untrusted code. In a second aspect, frames are popped on all thread stacks of all threads that are associated with the misbehaving code. Threads are generally deemed to be associated with the misbehaving code when the threads share a same object or the same resources as the thread that is associated with the misbehaving code.