Sudo, but with Rust


Disclaimer: You aren’t paying me to be your cybersecurity advisor, do the following at your peril!

The fine folks at Prossimo just announced their first release of a memory-safe version of sudo written in Rust (their blog post announcing the milestone can be found here). This development will ultimately lead to an entire class of bugs being avoided altogether or caught during compile time. Let’s test it out.

So I have spun up a Debian 12 virtual machine via QEMU and Virtual Machine Manager for this test. The sudo that comes with a Debian GNU/Linux distribution resides in the /usr/bin directory. I’ll be renaming both the su and sudo executables there to su.disabled and sudo.disabled here shortly, but first I’ll clone the GitHub repository with SSH to the system: git clone git@github.com:memorysafety/sudo-rs.git.

The docs state that the MSRV for this project is v1.70.0, so you’ll need to get that installed if you’re a madman and want to follow along. Issue a simple cargo build --release command to the terminal and after a few seconds I have the new memory-safe su and sudo binaries within the /target/release directory. I’d like to issue a few commands here, first I’ll fire off sudo chmod u+s for the respective binaries to set the setuid flag. I then move the binaries to the /usr/local/bin directory with the sudo command. Once this is done, I can make a bash alias to the sudo command that leads to the new memory-safe binaries.

Finally, I renamed the old su and sudo binaries to have a .disabled ending to them instead of outright deleting them. Viola, you now have a memory-safe version of sudo ready to go.

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