<Tag: exploit />

Heavy Is The Krown is a hard Linux kernel exploitation challenge from HTB Cyber Apocalypse 2026 that revolves around a kmalloc-512 Use-After-Free in a custom `/dev/krown` driver, letting an attacker hijack slab objects shared by “lord” and “vassal” structures. By overlaying a freed vassal with procfs `seq_file` data to defeat KASLR and then abusing the dangling pointer to overwrite `modprobe_path`, the exploit script gains root execution via a crafted helper script and extracts the flag.

The Emptiness Machine is a modern FSOP-based pwn challenge from Hack The Box’s Cyber Apocalypse 2026 that demonstrates how glibc file stream structures in a fully mitigated Linux x86_64 environment can still be abused for powerful exploitation. By combining a controlled leak from stdout to defeat ASLR with a carefully aligned House of Apple 2 attack on stderr, the solver script reliably turns program teardown (_IO_flush_all()) into a remote shell and captures the flag.