Microsoft Windows Cipher Suites For FalseStart MiTM Vulnerability (3155527)

# SPDX-FileCopyrightText: 2016 Greenbone AG
# Some text descriptions might be excerpted from (a) referenced
# source(s), and are Copyright (C) by the respective right holder(s).
#
# SPDX-License-Identifier: GPL-2.0-only

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.807326");
  script_version("2026-04-28T06:28:06+0000");
  script_tag(name:"cvss_base", value:"5.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:P/I:N/A:N");
  script_tag(name:"last_modification", value:"2026-04-28 06:28:06 +0000 (Tue, 28 Apr 2026)");
  script_tag(name:"creation_date", value:"2016-05-11 12:46:33 +0530 (Wed, 11 May 2016)");
  script_name("Microsoft Windows Cipher Suites For FalseStart MiTM Vulnerability (3155527)");

  script_tag(name:"summary", value:"This host is missing a security update
  according to Microsoft Security Advisory 3155527");

  script_tag(name:"vuldetect", value:"Checks if a vulnerable version is present on the target host.");

  script_tag(name:"insight", value:"The flaw exists in FalseStart which allows
  the TLS client to send application data before receiving and verifying the
  server Finished message.");

  script_tag(name:"impact", value:"Successful exploitation will allow an attacker
  to launch a man-in-the-middle (MiTM) attack to force the TLS client to encrypt
  the first flight of application_data records using the attacker's chosen cipher
  suite from the client's list.");

  script_tag(name:"affected", value:"- Microsoft Windows 8.1 x32/x64

  - Microsoft Windows Server 2012/2012R2");

  script_tag(name:"solution", value:"The vendor has released updates. Please see the references for more information.");

  script_tag(name:"solution_type", value:"VendorFix");

  script_tag(name:"qod_type", value:"executable_version");

  script_xref(name:"URL", value:"https://support.microsoft.com/en-us/kb/3151058");
  script_xref(name:"URL", value:"https://technet.microsoft.com/en-us/library/security/3155527");

  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2016 Greenbone AG");
  script_family("Windows");
  script_dependencies("smb_reg_service_pack.nasl");
  script_require_ports(139, 445);
  script_mandatory_keys("SMB/WindowsVersion");
  exit(0);
}


include("smb_nt.inc");
include("secpod_reg.inc");
include("version_func.inc");
include("secpod_smb_func.inc");

if(hotfix_check_sp(win2012:1, win2012R2:1, win8_1:1, win8_1x64:1) <= 0){
  exit(0);
}

sysPath = smb_get_systemroot();
if(!sysPath ){
  exit(0);
}

sysVer = fetch_file_version(sysPath:sysPath, file_name:"system32\Lsasrv.dll");
if(!sysVer){
  exit(0);
}

if (sysVer =~ "^(6\.2\.9200\.2)"){
  Vulnerable_range = "Less than - 6.2.9200.21830";
}
else if (sysVer =~ "^(6\.3\.9600\.1)"){
  Vulnerable_range = "Less than 6.3.9600.18298";
}

## Server 2012
if(hotfix_check_sp(win2012:1) > 0)
{
  if(version_is_less(version:sysVer, test_version:"6.2.9200.21830")){
     VULN = TRUE ;
  }
}

else if(hotfix_check_sp(win8_1:1, win8_1x64:1, win2012R2:1) > 0)
{
  if(version_is_less(version:sysVer, test_version:"6.3.9600.18298")){
    VULN = TRUE ;
  }
}

if(VULN)
{
  report = 'File checked:     ' + sysPath + "\system32\Lsasrv.dll" + '\n' +
           'File version:     ' + sysVer  + '\n' +
           'Vulnerable range: ' + Vulnerable_range + '\n' ;
  security_message(data:report);
  exit(0);
}