...
if ( param('trace') and param('trace') =~ /^[-.0-9a-zA-Z]+$/ ) { 
    print p( "Hello There- I am writing this from " 
           . "scratch so please be patient. Thanks!" ), 
        "<pre>"; 
 
    system( "/usr/sbin/traceroute", param('trace') ); 
...

[download]
Hoo boy. Watch out. You've used param() in both a scalar and a list context. In your security test, you look for things of interest, but in a scalar context, which means you are testing the first param value for trace if multiple values are defined. But then, you suck down all the param-values for trace when you fire off the traceroute. Guess what? You are now passing untested data to traceroute!

And given that there were some buffer overflow problems with traceroute if I recall my BUGTRAQ listings, giving root access to local users, you've just handed the keys to the kingdom to all-comers. Whee!

Security - it's not just for breakfast any more.

-- Randal L. Schwartz, Perl hacker

In reply to Possible Security Hole (was RE: Re: CGI and Traceroute) by merlyn
in thread CGI and Traceroute by Anonymous Monk

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