AVG Antivirus Code Injection Vulnerability

# SPDX-FileCopyrightText: 2017 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

CPE = "cpe:/a:avg:anti-virus";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.810835");
  script_version("2025-09-16T05:38:45+0000");
  script_cve_id("CVE-2017-5566");
  script_tag(name:"cvss_base", value:"7.2");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:L/Au:N/C:C/I:C/A:C");
  script_tag(name:"last_modification", value:"2025-09-16 05:38:45 +0000 (Tue, 16 Sep 2025)");
  script_tag(name:"severity_vector", value:"CVSS:3.0/AV:L/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2019-10-03 00:03:00 +0000 (Thu, 03 Oct 2019)");
  script_tag(name:"creation_date", value:"2017-04-04 17:45:27 +0530 (Tue, 04 Apr 2017)");
  script_name("AVG Antivirus Code Injection Vulnerability");

  script_tag(name:"summary", value:"AVG Antivirus is prone to a code injection vulnerability.");

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

  script_tag(name:"insight", value:"The flaw exists due to:

  - No use of Protected Processes feature, and therefore an attacker can enter an
    arbitrary Application Verifier Provider DLL under Image File Execution Options
    in the registry.

  - The self-protection mechanism is intended to block all local processes
    (regardless of privileges) from modifying Image File Execution Options for these
    products.");

  script_tag(name:"impact", value:"Successful exploitation of these
  vulnerabilities will allow a local attacker to bypass a self-protection
  mechanism, inject arbitrary code, and take full control of any AVG process
  via a 'DoubleAgent' attack.");

  script_tag(name:"affected", value:"AVG Antivirus 17.1 and earlier on Windows");

  script_tag(name:"solution", value:"No known solution was made available for at least one year since the disclosure
  of this vulnerability. Likely none will be provided anymore. General solution options are to upgrade to a newer
  release, disable respective features, remove the product or replace the product by another one.");

  script_tag(name:"solution_type", value:"WillNotFix");
  script_tag(name:"qod_type", value:"registry");
  script_xref(name:"URL", value:"https://cybellum.com/doubleagentzero-day-code-injection-and-persistence-technique");
  script_xref(name:"URL", value:"http://www.securityfocus.com/bid/97022");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2017 Greenbone AG");
  script_family("General");
  script_dependencies("secpod_avg_detect_win.nasl");
  script_mandatory_keys("avg/antivirus/detected");
  exit(0);
}

include("host_details.inc");
include("version_func.inc");

if( ! infos = get_app_version_and_location( cpe:CPE, exit_no_version:TRUE ) )
  exit( 0 );

version = infos["version"];
location = infos["location"];

if( version_is_less_equal( version:version, test_version:"17.1" ) ) {
  report = report_fixed_ver( installed_version:version, fixed_version:"None", install_path:location );
  security_message( port:0, data:report );
  exit( 0 );
}

exit( 99 );