Re: possible su local D.o.S

[Michal Zalewski <lcamtuf () coredump cx>]

On Thu, 13 Dec 2001, H VC wrote:

> [hvc@condor hvc] $ su `perl -e 'print "A" x 100000000'`
>
> and my box got practically frozen.
> I'm on a K6-II 500 , 128 MB and 550 of swap.

This is because you asked perl to create a 100 MB string by appending one
character enormous one hundred million times - and bash to cache this
"here" document. It has nothing to do with su. Su didn't even get
executed. It should work the same way for any other program (try 'sleep').

You can easily prevent this kind of attack by setting per-user or
per-process resource limits on your system.

-- 
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