Microsoft Windows SMB Registry : WinVNC's Key Permissions

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


include("compat.inc");

if (description)
{
 script_id(10553);
 script_version("1.33");
 script_cvs_date("Date: 2018/07/30 15:31:32");
 script_cve_id("CVE-2000-1164");
 script_bugtraq_id(1961);

 script_name(english:"Microsoft Windows SMB Registry : WinVNC's Key Permissions");
 script_summary(english:"Determines the access rights of a remote key");

 script_set_attribute(attribute:"synopsis", value:"Local users can connect to the system remotely.");
 script_set_attribute(attribute:"description", value:
"The registry key HKLM\Software\ORL\WinVNC3 is writeable and/or
readable by users who are not in the admin group.

This key contains the VNC password of this host, as well as other
configuration setup.

As this program allows remote access to this computer with the
privileges of the currently logged on users, you should fix this
problem.");
 script_set_attribute(attribute:"solution", value:
"Use regedt32 and set the permissions of this key to :

- admin group  : Full Control
    - system	   : Full Control
    - everyone	   : No access");
 script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/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_set_attribute(attribute:"vuln_publication_date", value:"2000/11/18");
 script_set_attribute(attribute:"plugin_publication_date", value:"2000/11/20");

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

 script_category(ACT_GATHER_INFO);
 script_copyright(english:"This script is Copyright (C) 2000-2018 Tenable Network Security, Inc.");
 script_family(english:"Windows");
 script_dependencies("netbios_name_get.nasl",
 		     "smb_login.nasl", "smb_registry_access.nasl");
 script_require_keys("SMB/transport", "SMB/name", "SMB/login", "SMB/password", "SMB/registry_access");
 script_require_ports(139, 445);
 exit(0);
}

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

access = get_kb_item("SMB/registry_access");
if(!access)exit(0, "Registry not accessible.");

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

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

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

hklm = RegConnectRegistry(hkey:HKEY_LOCAL_MACHINE);
if ( isnull(hklm) )
{
 NetUseDel();
 audit(AUDIT_REG_FAIL);
}

key = "Software\ORL\WinVNC3";

key_h = RegOpenKey(handle:hklm, key:key, mode:MAXIMUM_ALLOWED | ACCESS_SYSTEM_SECURITY);
if(!isnull(key_h))
{
 rep = RegGetKeySecurity (handle:key_h, type: DACL_SECURITY_INFORMATION | SACL_SECURITY_INFORMATION | GROUP_SECURITY_INFORMATION | OWNER_SECURITY_INFORMATION);
 if(!isnull(rep) && registry_key_writeable_by_non_admin(security_descriptor:rep))
 {
   security_hole(port);
 }
 RegCloseKey (handle:key_h);
}

RegCloseKey (handle:hklm);
NetUseDel();