Re: possible su local D.o.S

From: Flavio Veloso (flaviovsat_private)
Date: Thu Dec 13 2001 - 08:39:41 PST

  • Next message: Michal Zalewski: "Re: possible su local D.o.S"

    On Thu, 13 Dec 2001, H VC wrote:
    
    Did you ever tried the command below?
    
        $ perl -e 'print "A" x 100000000' > /dev/null
    
    > Hi,
    >
    > Dave Ahmad ( daat_private ) tell me to post this.
    >
    > On a default installation of RedHat 7.2 sh-utils-2.0.11-5 is installed. On a
    > RH 7.1 sh-utils version is 2.0.13 ... ¿ Why this ?
    >
    > On my RH 7.2 I tried this :
    >
    > [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.
    >
    > I have noticed that it only seems to work whe I parse a user string
    > to su near the limit ( free mem. + swap ). Over this range is detected
    > as a too many large string but also just over the available memory...
    >
    > Why su allows so large user names ?
    > How long could be a unix/linux user name ?
    > Why do not su limit the size of username to the unix/linux max. size of a
    > user name ?
    >
    > Thanks.
    >
    > HVC
    >
    > Hugo Vázquez Caramés
    > IT Security Services Winmat
    > Barcelona
    > Spain
    >
    > overclocking_a_la_abuelaat_private
    >
    >
    >
    >
    >
    > _________________________________________________________________
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    >
    
    -- 
    Flávio
    



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