H4X - Research https://research.h4x.cz In search of interesting behaviour. en 1440 Mon, 27 Oct 2025 18:53:53 +0100 https://www.rssboard.org/rss-specification https://research.h4x.cz/data/D6JcuUXAjQRsOvwFuTAoe4IcAhaZkunH/against_demons.ascii.html https://research.h4x.cz/data/D6JcuUXAjQRsOvwFuTAoe4IcAhaZkunH/against_demons.ansi.html daily Healing Fatally Wounded ELF: Time Travel with QEMU Snapshots (x86-64) https://research.h4x.cz/html/2025/2025-10-24--touching_small_elfs-p3-broken_time-machine.html Fri, 24 Oct 2025 00:00:00 +0000 https://research.h4x.cz/html/2025/2025-10-24--touching_small_elfs-p3-broken_time-machine.html ELF Magic Gone Wrong: Debugging SEGFAULTs (x86-64) https://research.h4x.cz/html/2025/2025-10-06--touching_small_elfs-p2-segfaults_everywhere.html Mon, 06 Oct 2025 00:00:00 +0000 https://research.h4x.cz/html/2025/2025-10-06--touching_small_elfs-p2-segfaults_everywhere.html Touching Small ELFs: Fixing Broken Tools (x86-64) https://research.h4x.cz/html/2025/2025-09-11--touching_small_elfs-p1-broken_tools.html Thu, 11 Sep 2025 00:00:00 +0000 https://research.h4x.cz/html/2025/2025-09-11--touching_small_elfs-p1-broken_tools.html radare2: Working with not-so-valid x86-64 ELFs https://research.h4x.cz/html/2025/2025-07-23--radare2_working_with_not-so-valid_elfs.html Wed, 23 Jul 2025 00:00:00 +0000 https://research.h4x.cz/html/2025/2025-07-23--radare2_working_with_not-so-valid_elfs.html Kprobes, Linux ELF loader, and C templating https://research.h4x.cz/html/2025/2025-06-20--kprobes_kernel_symbol_two_addresses_and_c_templating.html Fri, 20 Jun 2025 00:00:00 +0000 https://research.h4x.cz/html/2025/2025-06-20--kprobes_kernel_symbol_two_addresses_and_c_templating.html Ghetto Reversing, Hacking, Patching and Incidentally Fixing a Bug in FBReader https://research.h4x.cz/html/2024/2024-06-03--binary_reversing_and_hacking-case_fbreader.html Mon, 03 Jun 2024 00:00:00 +0000 https://research.h4x.cz/html/2024/2024-06-03--binary_reversing_and_hacking-case_fbreader.html WebP Polyglot II: Executable Picture https://research.h4x.cz/html/2023/2023-09-01--webp_polyglot_ii-script.html Fri, 01 Sep 2023 00:00:00 +0000 https://research.h4x.cz/html/2023/2023-09-01--webp_polyglot_ii-script.html WebP Polyglot I: Bootable Picture https://research.h4x.cz/html/2023/2023-08-08--webp_polyglot_i-bootable_picture.html Tue, 08 Aug 2023 00:00:00 +0000 https://research.h4x.cz/html/2023/2023-08-08--webp_polyglot_i-bootable_picture.html Concealing Linux Namespaces Within a File Descriptor https://research.h4x.cz/html/2023/2023-04-17--linux--hiding_namespaces_within_a_fd.html Mon, 17 Apr 2023 00:00:00 +0000 https://research.h4x.cz/html/2023/2023-04-17--linux--hiding_namespaces_within_a_fd.html AppArmor Signal Filtering and TTY Signals: Killing the Unkillable https://research.h4x.cz/html/2023/2023-02-28--linux--apparmor_signal_filter_vs_tty_signals--ctrl-z-ptrace.html Tue, 28 Feb 2023 00:00:00 +0000 https://research.h4x.cz/html/2023/2023-02-28--linux--apparmor_signal_filter_vs_tty_signals--ctrl-z-ptrace.html "Scripting" with C -- Making Quick Proof of Concepts in C https://research.h4x.cz/html/2022/2022-10-11--scripting_in_c.html Tue, 11 Oct 2022 00:00:00 +0000 https://research.h4x.cz/html/2022/2022-10-11--scripting_in_c.html Quick and Dirty Disassembler in Python3 https://research.h4x.cz/html/2022/2022-05-03--quick_and_dirty_disassembler_in_python.html Tue, 03 May 2022 00:00:00 +0000 https://research.h4x.cz/html/2022/2022-05-03--quick_and_dirty_disassembler_in_python.html Quick and dirty way to create your own assembler in nasm https://research.h4x.cz/html/2022/2022-04-27--howto_create_your_own_instruction_set_in_nasm-quick_and_dirty_vm_code.html Wed, 27 Apr 2022 00:00:00 +0000 https://research.h4x.cz/html/2022/2022-04-27--howto_create_your_own_instruction_set_in_nasm-quick_and_dirty_vm_code.html CVE-2022-1271: (x)zgrep code execution caused by new lines in a filename https://research.h4x.cz/html/2022/2022-04-11--hack--zgrep_multiline_filename_code_execution.html Mon, 11 Apr 2022 00:00:00 +0000 https://research.h4x.cz/html/2022/2022-04-11--hack--zgrep_multiline_filename_code_execution.html Linux: bind and connect to port 0 with iptables REDIRECT or DNAT https://research.h4x.cz/html/2021/2021-12-31--linux--bind_and_connect_to_port_0_with_iptables_redirect_or_dnat.html Fri, 31 Dec 2021 00:00:00 +0000 https://research.h4x.cz/html/2021/2021-12-31--linux--bind_and_connect_to_port_0_with_iptables_redirect_or_dnat.html Linux: minimal viable x86 ELF64 static binary https://research.h4x.cz/html/2019/2019-10-22--linux--minimal_viable_x86_elf64_static_binary.html Tue, 22 Oct 2019 00:00:00 +0000 https://research.h4x.cz/html/2019/2019-10-22--linux--minimal_viable_x86_elf64_static_binary.html