also @ TechSpot: California man finds limits of Verizon FiOS unlimited data broadband service: 77TB

Linux distributions still vulnerable to fork bombing

By Derek Sooman

On March 20, 2005, 2:59 AM

A fork bomb is a UNIX system attack, commonly written in one line of C or shell code, that "explodes" by recursively spawning copies of itself, until it eats all the process table entries and brings the system down. It’s been known about for a long time, and it would be expected that modern Linux distributions would be immune to this kind of attack. Think again.

I wrote up a very simple bourne shell script on my work machine, which runs Mandrake Linux, and executed it under my non-privileged account. Within seconds, the machine was brought to its knees -- totally crippled and unusable. I stared at my screen in disbelief for a few moments, totally stunned with what had just happened.

The author of the article tested on Mandrake, Red Hat, Gentoo and other distributions and found the problem to still exist.

[15:16:53] <@darks> but I mean, I could have killed ur box
[15:17:04] <+IronBar> no, you couldn't have.
[15:17:08] <@darks> wanna bet ?
[15:17:27] <@darks> forkbomb it

No tags on this story

User Comments: 29

Got something to say? Post a comment
  1. Pretty sure the last 2 posts before you wernt arguing.. P66: Why put go.bat /C when go.bat will run out the file/execute the file? why would you need the /C?
  2. [b]Originally posted by colin.horne:[/b][quote]People - relax, please!Thank you to the author for sharing a potentially serious security problem. Thank you to all the users who've explained how to fix it (/etc/security/limits.conf). Thank you to those who've corrected the author, pointing out that it's a configuration error more than a kernel bug.Now, could we please find a kernel bug, and stop arguing :-)Cheers--Colin[/quote]That was pretty well said. Thank you.
  3. [b]Originally posted by ---agissi---:[/b][quote]what does the /C command do here Soul?[/quote]It causes CMD to terminate after it is finished executing the batch. I figured this way I could have more windows, rather then fewer stalled windows. Not sure though on what the effect would be by removing it.
  4. Hi all people First post for me, but i have great news for you.No forkbomb more on linux, just need a little setting.Set parameter "ulimit" made fork not usable on every unix and linux system.Bye allRaouL.

Recently commented stories

Post a new comment

Social Login & Guest Posting TechSpot Members
Login here or sign up for free,
it takes about a minute.
Get complete access to the TechSpot community. Join thousands of technology enthusiasts that contribute and share knowledge in our forum. Get a private inbox, upload your own photo gallery and more.
TechSpot on:

Subscribe to TechSpot

Get free exclusive content, learn about new features and breaking tech news.