NetSupport Manager Client Spoofing Remote Authentication Bypass

#
# (C) Tenable Network Security, Inc.
#


include("compat.inc");

if (description)
{
  script_id(26071);
  script_version("1.14");
 script_cvs_date("Date: 2018/11/15 20:50:27");

  script_cve_id("CVE-2007-5057");
  script_bugtraq_id(25761);

  script_name(english:"NetSupport Manager Client Spoofing Remote Authentication Bypass");
  script_summary(english:"Checks version of NSM's pcicl32.dll");

 script_set_attribute(attribute:"synopsis", value:
"The remote Windows host has a program that is prone to an
authentication bypass attack.");
 script_set_attribute(attribute:"description", value:
"NetSupport Manager (NSM), a multi-platform remote control application,
is installed on the remote host.

According to its version, the NetSupport Manager client component on
the remote host does not properly handle authentication sessions. A
remote attacker may be able to leverage this issue to pose as the
NetSupport Manager, associate to the NSM client, and gain complete
control of the affected system.");
 script_set_attribute(attribute:"see_also", value:"https://www.securityfocus.com/archive/1/480240/30/0/threaded");
 script_set_attribute(attribute:"see_also", value:"http://www.netsupportsoftware.com/support/td.asp?td=543" );
 script_set_attribute(attribute:"solution", value:"Upgrade to NetSupport Manager version 10.20.0004 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_attribute(attribute:"exploitability_ease", value:"No known exploits are available");
  script_set_attribute(attribute:"exploit_available", value:"false");
 script_cwe_id(287);

 script_set_attribute(attribute:"plugin_publication_date", value:"2007/09/24");

script_set_attribute(attribute:"plugin_type", value:"local");
script_end_attributes();


  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows");

  script_copyright(english:"This script is Copyright (C) 2007-2018 Tenable Network Security, Inc.");

  script_dependencies("smb_hotfixes.nasl");
  script_require_keys("SMB/Registry/Enumerated");
  script_require_ports(139, 445);

  exit(0);
}


include("audit.inc");
include("smb_func.inc");


# Figure out where the installer recorded information about it.
key = NULL;

list = get_kb_list("SMB/Registry/HKLM/SOFTWARE/Microsoft/Windows/CurrentVersion/Uninstall/*/DisplayName");
if (isnull(list)) exit(0);

foreach name (keys(list))
{
  prod = list[name];
  if (prod && "NetSupport Manager" >< prod)
  {
    key = ereg_replace(pattern:"^SMB\/Registry\/HKLM\/(.+)\/DisplayName$", replace:"\1", string:name);
    key = str_replace(find:"/", replace:"\", string:key);
    break;
  }
}
if (isnull(key)) exit(0);


# Connect to the appropriate share.
if (!get_kb_item("SMB/Registry/Enumerated")) exit(1, "KB 'SMB/Registry/Enumerated' not set to TRUE.");

port    =  kb_smb_transport();
login   =  kb_smb_login();
pass    =  kb_smb_password();
domain  =  kb_smb_domain();

if(! smb_session_init()) audit(AUDIT_FN_FAIL, 'smb_session_init');

rc = NetUseAdd(login:login, password:pass, domain:domain, share:"IPC$");
if (rc != 1)
{
  NetUseDel();
  audit(AUDIT_SHARE_FAIL,"IPC$");
}


# Connect to remote registry.
hklm = RegConnectRegistry(hkey:HKEY_LOCAL_MACHINE);
if (isnull(hklm))
{
  NetUseDel();
  audit(AUDIT_REG_FAIL);
}


# Find out where it was installed.
path = NULL;

key_h = RegOpenKey(handle:hklm, key:key, mode:MAXIMUM_ALLOWED);
if (!isnull(key_h))
{
  item = RegQueryValue(handle:key_h, item:"InstallLocation");
  if (!isnull(item))
  {
    path = item[1];
    path = ereg_replace(pattern:"^(.+)\\$", replace:"\1", string:path);
  }

  RegCloseKey(handle:key_h);
}
if (isnull(path))
{
  RegCloseKey(handle:hklm);
  NetUseDel();
  exit(0);
}


# Make sure it's a client install.
client = FALSE;

key = "SOFTWARE\NetSupport Manager\InstalledFeatures";
key_h = RegOpenKey(handle:hklm, key:key, mode:MAXIMUM_ALLOWED);
if (!isnull(key_h))
{
  item = RegQueryValue(handle:key_h, item:"client");
  if (!isnull(item) && 1 == item[1]) client = TRUE;
  RegCloseKey(handle:key_h);
}
RegCloseKey(handle:hklm);
if (!client)
{
  NetUseDel();
  exit(0);
}


# Determine the version of PCICL32.DLL.
share = ereg_replace(pattern:"^([A-Za-z]):.*", replace:"\1$", string:path);
dll =  ereg_replace(pattern:"^[A-Za-z]:(.*)", replace:"\1\PCICL32.DLL", string:path);
NetUseDel(close:FALSE);

rc = NetUseAdd(login:login, password:pass, domain:domain, share:share);
if (rc != 1)
{
  NetUseDel();
  audit(AUDIT_SHARE_FAIL,share);
}

fh = CreateFile(
  file:dll,
  desired_access:GENERIC_READ,
  file_attributes:FILE_ATTRIBUTE_NORMAL,
  share_mode:FILE_SHARE_READ,
  create_disposition:OPEN_EXISTING
);
ver = NULL;
if (!isnull(fh))
{
  ver = GetFileVersion(handle:fh);
  CloseFile(handle:fh);
}
NetUseDel();


# Check the version number.
if (!isnull(ver))
{
  if (
    (ver[0] >= 5 && ver[0] < 10) ||
    (
      ver[0] == 10 &&
      (
        ver[1] < 20 ||
        (ver[1] == 20 && ver[2] < 4)
      )
    )
  )
  {
    if (ver[2] < 10) ver[2] = string("000", ver[2]);
    else if (ver[2] < 100) ver[2] = string("00", ver[2]);
    else if (ver[2] < 1000) ver[2] = string("0", ver[2]);
    version = string(ver[0], ".", ver[1], ".", ver[2]);

    report = string(
      "Version ", version, " of the NSM client is installed under :\n",
      "\n",
      "  ", path, "\n"
    );
    security_hole(port:port, extra:report);
  }
}