NetBSD is an open-source, Unix-like operating system known for its portability, lightweight design, and robustness across a wide array of hardware platforms. Initially released in 1993, NetBSD was one of the first open-source operating systems based on the Berkeley Software Distribution (BSD) lineage, alongside FreeBSD and OpenBSD. NetBSD’s development has been led by a collaborative community and is particularly recognized for its “clean” and well-documented codebase, a factor that has made it a popular choice among users interested in systems programming and cross-platform compatibility. ↫ André Machado I’m not really sure what to make of this article, since it mostly reads like an advertisement for NetBSD, but considering NetBSD is one of the lesser-talked about variants of an operating system family that already sadly plays second fiddle to the Linux behemoth, I don’t think giving it some additional attention is really hurting anybody. The article is still gives a solid overview of the history and strengths of NetBSD, which makes it a good introduction. I have personally never tried NetBSD, but it’s on my list of systems to try out on my PA-RISC workstation since from what I’ve heard it’s the only BSD which can possibly load up X11 on the Visualize FX10pro graphics card it has (OpenBSD can only boot to a console on this GPU). While I could probably coax some cobbled-together Linux installation into booting X11 on it, where’s the fun in that? Do any of you lovely readers use NetBSD for anything? FreeBSD and even OpenBSD are quite well represented as general purpose operating systems in the kinds of circles we all frequent, but I rarely hear about people using NetBSD other than explicitly because it supports some outdated, arcane architecture in 2024.

NetBSD mail.local(8) local root exploit that leverages a race condition as noted in NetBSD-SA2016-006.

This Metasploit module attempts to exploit a race condition in mail.local with the SUID bit set on: NetBSD 7.0 - 7.0.1 (verified on 7.0.1), NetBSD 6.1 - 6.1.5, and NetBSD 6.0 - 6.0.6. Successful exploitation relies on a crontab job with root privilege, which may take up to 10min to execute.

NetBSD stack clash proof of concept exploit.

NetBSD Security Advisory 2004-010 - Some of the functions in /usr/src/sys/compat/ which implement execution of foreign binaries (such as Linux, FreeBSD, IRIX, OSF1, SVR4, HPUX, and ULTRIX) use argument data in unsafe ways prior to calling the kernel syscall.

NetBSD uses the ptrace(2) system call to trace and debug other processes. The debugging process can also modify the internal registers, including the status (PSL) register, for the process being debugged. Besides the normal user-accessible flags, the VAX hardware also stores information about privilege levels and used stacks in the PSL. Those flags are only altered via the instruction REI (return from interrupt) or LDPCTX (load process context) and cannot be modified while running in "user" mode. NetBSD security page here.