The historical vulnerability of NULL pointer dereferences in macOS that previously allowed attackers to execute arbitrary code with kernel privileges has been unveiled recently by security analysts. NULL pointer dereferences occur when the operating system attempts to access memory address zero, which normally causes a crash. The kernel would execute a function pointer from address zero, thinking it was calling a valid kernel function, but instead executing attacker code. The exploit combined a NULL pointer dereference in IOKit with an information leak to achieve root privileges, bypassing several security mechanisms of the time. ARM64 processors implement Privileged Execute Never (PXN) and Privileged Access Never (PAN) technologies that prevent the kernel from executing or accessing user-space memory without explicit intent. While historical examples demonstrate how NULL dereferences were once powerful attack vectors, Apple has effectively mitigated these vulnerabilities through comprehensive security controls. On contemporary macOS systems, especially those running on Apple Silicon, multiple layers of defense prevent exploitation of NULL pointer dereferences. Despite modern systems having robust mitigations, understanding these historical attack vectors provides valuable insights into Apple’s security evolution.
This Cyber News was published on cybersecuritynews.com. Publication date: Tue, 11 Mar 2025 11:00:07 +0000