With the latest Linux kernel, the fuzzing process will be easier not only for our team. Thanks to Denis Valeev, who discovered, prepared, and contributed the patch to kernel v.5.16.5.
The discovered bug breaks nyx-fuzz (also included in AFL++ code base) that uses VMware backdoor as an alternative way for hypercall from guest user-mode. With this bug, a hypercall is interpreted as a GP and leads to process termination. Bug occurs on GP triggered by VMware backdoor when eax value is unaligned. eax alignment check should not be applied to non-SVM instructions because it leads to incorrect omission of the instructions emulation. The solution is to apply alignment check only to SVM instructions.
The paper introduces the case study for attack surface analysis and monitoring with practical application of open-source intelligence (OSINT) methods. The case is based on the perimeters of healthcare organizations and aims to introduce the threat landscape of healthcare industry as well as methods to collect information about entry points and assets on network perimeter. Techniques and tools in this paper are not limited by organization type and can be applied for different network assets to prepare initial information during first stage of penetration testing and red team operations.