In software development, a NULL pointer is a pointer variable that does not reference any valid memory location. Dereferencing such a pointer—attempting to access the memory it supposedly points to—results in undefined behaviour. In many systems, this leads to crashes, data corruption, or even exploitable vulnerabilities.
At its core, a Use After Free vulnerability occurs when a program continues to use memory after it has been freed or deallocated. This behaviour can result in undefined behaviour, ranging from crashes and data corruption to critical security breaches, including arbitrary code execution.
Out-of-Bounds Read occurs when a program reads data past the allocated boundary of a buffer. This behaviour typically arises from improper validation of input data or incorrect indexing in memory operations. By exploiting this weakness, attackers can gain unauthorised access to sensitive information, potentially leading to security violations.