Vulnerabilities > CVE-2017-8621 - Open Redirect vulnerability in Microsoft Exchange Server 2010/2013/2016

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

include("compat.inc");

if (description)
{
  script_id(101522);
  script_version("1.9");
  script_cvs_date("Date: 2019/11/12");

  script_cve_id("CVE-2017-8559", "CVE-2017-8560", "CVE-2017-8621");
  script_bugtraq_id(99448, 99449, 99533);
  script_xref(name:"MSKB", value:"4018588");
  script_xref(name:"MSFT", value:"MS17-4018588");

  script_name(english:"KB4018588: Security Update for Microsoft Exchange Server");
  script_summary(english:"Checks the version of ExSetup.exe.");

  script_set_attribute(attribute:"synopsis", value:
"The remote Microsoft Exchange Server is affected by multiple
vulnerabilities.");
  script_set_attribute(attribute:"description", value:
"The remote Microsoft Exchange Server is missing a security update. It
is, therefore, affected by multiple vulnerabilities :

  - Multiple cross-site scripting (XSS) vulnerabilities
    exist in Microsoft Exchange Outlook Web Access (OWA)
    due to improper validation of user-supplied input in web
    requests. An unauthenticated, remote attacker can
    exploit these, via a specially crafted link, to execute
    arbitrary script code in a user's browser session.
    (CVE-2017-8559, CVE-2017-8560)

  - A cross-site redirection vulnerability exists due to
    improper validation of user-supplied input before
    returning it to users. An unauthenticated, remote
    attacker can exploit this, by convincing a user to
    follow a link, to cause the user to load a malicious
    website, which then can be used to conduct further
    attacks. (CVE-2017-8621)");
  # https://support.microsoft.com/en-us/help/4018588/description-of-the-security-update-for-microsoft-exchange-july-11-2017
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?eb2a7256");
  script_set_attribute(attribute:"solution", value:
"Microsoft has released a set of patches for Exchange Server 2010,
2013, and 2016.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:P/I:P/A:N");
  script_set_cvss_temporal_vector("CVSS2#E:U/RL:OF/RC:C");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/RC:C");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2017-8621");

  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:"2017/07/11");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/07/11");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/07/13");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:exchange_server");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2017-2019 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("ms_bulletin_checks_possible.nasl", "microsoft_exchange_installed.nbin");
  script_require_keys("SMB/MS_Bulletin_Checks/Possible");
  script_require_ports(139, 445, "Host/patch_management_checks");

  exit(0);
}

include("audit.inc");
include("smb_func.inc");
include("smb_hotfixes.inc");
include("smb_hotfixes_fcheck.inc");
include("misc_func.inc");
include("install_func.inc");

get_kb_item_or_exit('SMB/MS_Bulletin_Checks/Possible');

bulletin = 'MS17-07';
kb = "4018588";
kbs = make_list(kb);

if (get_kb_item('Host/patch_management_checks')) hotfix_check_3rd_party(bulletin:bulletin, kbs:kbs, severity:SECURITY_WARNING);

install = get_single_install(app_name:"Microsoft Exchange");

path = install["path"];
version = install["version"];
release = install["RELEASE"];

if (release != 150 && release != 151 && release != 140)
  audit(AUDIT_INST_VER_NOT_VULN, 'Exchange', version);

if (!empty_or_null(install["SP"]))
  sp = install["SP"];
if (!empty_or_null(install["CU"]))
  cu = install["CU"];

# This affects 2010 SP3 (140) regardless of CU so skipping this check for it
if (((release == 150 || release == 151) && isnull(cu)) ||
   (release == 150 && cu != 4 && cu != 16) ||
   (release == 151 && cu != 5))
  audit(AUDIT_INST_VER_NOT_VULN, 'Exchange', version);

if (release == 140) # 2010 SP3
{
  fixedver = "14.3.361.1";
}
else if (release == 150) # 2013 SP1 AKA CU4
{
  if (cu == 4)
    fixedver = "15.0.847.55";
  else if (cu == 16)
    fixedver = "15.0.1293.4";
}
else if (release == 151) # Exchange Server 2016
{
  if (cu == 5)
    fixedver = "15.1.845.36";
}

if (fixedver && hotfix_is_vulnerable(path:hotfix_append_path(path:path, value:"Bin"), file:"ExSetup.exe", version:fixedver, bulletin:bulletin, kb:kb))
{
  set_kb_item(name:'SMB/Missing/' + bulletin, value:TRUE);
  set_kb_item(name:'www/0/XSS', value:TRUE);
  hotfix_security_warning();
  hotfix_check_fversion_end();
  exit(0);
}
else
{
  hotfix_check_fversion_end();
  audit(AUDIT_HOST_NOT, 'affected');
}