Re: buffer overflow in nslookup?

From: www.devoid.net (adminat_private)
Date: Sun Aug 30 1998 - 18:47:18 PDT

  • Next message: Benjamin J Stassart: "Re: buffer overflow in nslookup?"

    my last mail didn't go out so this time i wont go through all the examples
    because i do not have the time.
    none of these buffer overruns core my nslookup ( bind-8.1.2 )
    i am running a duel processor x86,
    pentium classic,
    and Cyril
    
    not that the CPA matters..
    
    where did the nslookup in these examples origionate ?
    
    
    
    On 30-Aug-98 Brandon Reynolds wrote:
    > On Sat, 29 Aug 1998, Peter van Dijk wrote:
    >
    >> *** zopie.attic.vuurwerk.nl can't find AA....AAA: Unspecified error
    >> Segmentation fault (core dumped)
    >> [peter@koek] ~$ nslookup `perl -e 'print "A" x 1000;'`
    >> Server:  zopie.attic.vuurwerk.nl
    >> Address:  10.10.13.1
    >>
    >> Segmentation fault (core dumped)
    >>
    >> At first, this does not seem a problem: nslookup is not suid root or
    >> anything.
    >> But several sites have cgi-scripts that call nslookup... tests show that
    >> these
    >> will coredump when passed enough characters. Looks exploitable to me...
    >
    > The offending line is line 684 in main.c:
    >
    >     sscanf(string, " %s", host);        /* removes white space */
    >
    > It could easily remedied by inserting something like this before it.
    >
    >     if(strlen(string) > NAME_LEN) {
    >       fprintf(stderr,"host name too long.\n");
    >       exit(1);
    >     }
    >
    > The code seems to be littered with sscanf's, but I guess the command line
    > is probably the only critical concern since it's not suid.
    >
    > Brandon Reynolds                                   bmrat_private
    > The University of Akron              (330) 972-6776 fax (330) 374-8630
    > Mathematical Sciences                 http://www.math.uakron.edu/~bmr/
    
    --------------------------
    E-Mail: adminat_private
    Date: 30-Aug-98
    Time: 18:42:45
          www.devoid.net
    --------------------------
    



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