Plash is an open source system utility for sandboxing Linux applications. Plash aims to downgrade the threats posed by executing untrusted programs by running them in a secure, restricted execution environment with the minimum authority and privileges they need to do their job.

Plash virtualizes the file name-space and provides per-sandboxed-process name-spaces. It locks the sandboxed processes in a very minimal chrooted environment and restricts access to the kernel-based system calls.

The sandboxed process accesses the filesystem by making remote procedure calls across a socket to a server process. Plash dynamically links sandboxed programs with a modified version of GNU libc (glibc), which replaces the filename-related calls (such as open()) so that they make RPCs across the socket instead of using the usual system calls.

Plash’s sandboxing mechanism works on unmodified Linux kernels - 2.6, 2.4 and earlier - and can run normal Linux executables, provided they are dynamically linked. Plash can be used to run servers, command line tools, and applications with graphical user interfaces.

Download Plash here.