Cisco WebEx Extension for Chrome < 1.0.12 'atgpcext' Library GPC Sanitization RCE (cisco-sa-20170717-webex)

#%NASL_MIN_LEVEL 70300
#
# (C) Tenable Network Security, Inc.
#

include('deprecated_nasl_level.inc');
include('compat.inc');

if (description)
{
  script_id(101816);
  script_version("1.5");
  script_set_attribute(attribute:"plugin_modification_date", value:"2022/04/11");

  script_cve_id("CVE-2017-6753");
  script_bugtraq_id(99614);
  script_xref(name:"CISCO-SA", value:"cisco-sa-20170717-webex");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvf15012");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvf15020");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvf15030");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvf15033");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvf15036");
  script_xref(name:"CISCO-BUG-ID", value:"CSCvf15037");
  script_xref(name:"IAVA", value:"2017-A-0216");

  script_name(english:"Cisco WebEx Extension for Chrome < 1.0.12 'atgpcext' Library GPC Sanitization RCE (cisco-sa-20170717-webex)");

  script_set_attribute(attribute:"synopsis", value:
"A browser extension installed on the remote host is affected by a
remote code execution vulnerability.");
  script_set_attribute(attribute:"description", value:
"The Cisco WebEx Extension for Chrome installed on the remote host is a
version prior to 1.0.12. It is, therefore, affected by a remote code
execution vulnerability in the 'atgpcext' library due to incomplete
GPC sanitization. An unauthenticated, remote attacker can exploit
this, by convincing a user to visit a specially crafted website, to
execute arbitrary code with the privileges of the affected browser.");
  # https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170717-webex
  script_set_attribute(attribute:"see_also", value:"http://www.nessus.org/u?0a976aaa");
  script_set_attribute(attribute:"see_also", value:"https://bugs.chromium.org/p/project-zero/issues/detail?id=1324");
  script_set_attribute(attribute:"see_also", value:"https://thehackernews.com/2017/07/cisco-webex-vulnerability.html");
  script_set_attribute(attribute:"solution", value:
"Upgrade to Cisco WebEx Extension for Chrome version 1.0.12 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:M/Au:N/C:C/I:C/A:C");
  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:U/C:H/I:H/A:H");
  script_set_cvss3_temporal_vector("CVSS:3.0/E:U/RL:O/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:"in_the_news", value:"true");

  script_set_attribute(attribute:"vuln_publication_date", value:"2017/07/17");
  script_set_attribute(attribute:"patch_publication_date", value:"2017/07/17");
  script_set_attribute(attribute:"plugin_publication_date", value:"2017/07/19");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:google:chrome");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:cisco:webex");
  script_set_attribute(attribute:"stig_severity", value:"II");
  script_set_attribute(attribute:"thorough_tests", value:"true");
  script_end_attributes();

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

  script_copyright(english:"This script is Copyright (C) 2017-2022 Tenable Network Security, Inc.");

  script_dependencies("win_chrome_browser_addons.nbin");
  script_require_keys("SMB/Google_Chrome/Installed", "SMB/WindowsVersion");
  script_require_ports(139, 445);

  exit(0);
}

include("audit.inc");
include("datetime.inc");
include("misc_func.inc");
include("smb_func.inc");
include("smb_hotfixes.inc");
include("smb_reg_query.inc");
include("smb_hotfixes_fcheck.inc");
include("browser.inc");
include("json.inc");

addons = get_browser_addons(browser:"Chrome", type:"all", name:"Cisco WebEx Extension", exit_on_fail:TRUE);
ext_report = "";
report = "";
ver = NULL;
vuln = 0;
users = make_array();

hotfix_check_fversion_init();

foreach addon(addons["addons"])
{
  if(users[addon['user']]) continue;

  # Try to get active version from preferences
  path = pregmatch(pattern:"(.*)Extensions.*", string:addon['path']);
  path = path[1] + "Secure Preferences";
  prefs = hotfix_get_file_contents(path:path);

  if(prefs['error'] == 0)
  {
    prefs = json_read(prefs['data']);
    ver = prefs[0]["extensions"]["settings"]["jlhmfgmfgeifomenelglieieghnjghma"]["manifest"]["version"];
    users[addon['user']] = TRUE;
  }

  if(empty_or_null(ver))
  {
    if (report_paranoia < 2)
    {
      hotfix_check_fversion_end();
      audit(AUDIT_PARANOID);
    }
    ver = chomp(addon['version']);
  }

  if(ver_compare(ver:ver, fix:"1.0.12", strict:FALSE) < 0)
  {
    vuln += 1;
    ext_report += '\n' +
                  '\n  User        : ' + addon['user'] +
                  '\n  Version     : ' + addon['version'] +
                  '\n  Update date : ' + addon['update_date'] +
                  '\n  Path        : ' + addon['path'] +
                  '\n';
  }
}

hotfix_check_fversion_end();

if(vuln)
{
  port = get_kb_item('SMB/transport');
  if (!port) port = 445;

  if(vuln > 1) user = "users have";
  else user = "user has";

  report += '\n' +
            "The following " + user + " a vulnerable version of the Cisco WebEx Extension for Chrome installed :" +
            ext_report +
            '\n' +
            "Fix : Upgrade to to Cisco WebEx Extension version 1.0.12 or later." +
            '\n';
  security_report_v4(severity:SECURITY_HOLE, port:port, extra:report);
}
else audit(AUDIT_INST_VER_NOT_VULN, "Cisco WebEx Extension for Chrome");