Avast Antivirus (All Editions) < 19.8 DLL Preloading Vulnerability - Windows

# SPDX-FileCopyrightText: 2019 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:avast:antivirus";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.107737");
  script_version("2024-02-15T05:05:40+0000");
  script_tag(name:"cvss_base", value:"4.4");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:M/Au:N/C:P/I:P/A:P");
  script_tag(name:"last_modification", value:"2024-02-15 05:05:40 +0000 (Thu, 15 Feb 2024)");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2019-10-29 13:12:00 +0000 (Tue, 29 Oct 2019)");
  script_tag(name:"creation_date", value:"2019-10-26 18:39:30 +0200 (Sat, 26 Oct 2019)");

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

  script_cve_id("CVE-2019-17093");

  script_name("Avast Antivirus (All Editions) < 19.8 DLL Preloading Vulnerability - Windows");

  script_copyright("Copyright (C) 2019 Greenbone AG");
  script_category(ACT_GATHER_INFO);
  script_family("General");
  script_dependencies("gb_avast_av_detect_win.nasl");
  script_mandatory_keys("avast/antivirus/detected");

  script_tag(name:"summary", value:"Avast Antivirus is prone to a dll preloading vulnerability.");

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

  script_tag(name:"insight", value:"The vulnerability gives attackers the ability to:

  - load and execute malicious payloads using multiple signed services, within the context of Avast
  signed processes

  - bypass the part of the self-defense mechanism that should prevent an attacker from tampering with processes
  and files of Avast Antivirus and load an arbitrary DLL into the Antivirus process

  - load and execute malicious payloads in a persistent way, each time the services are loaded.");

  script_tag(name:"impact", value:"The vulnerability can be used to achieve self-defense bypass, defense evasion,
  persistence and privilege escalation.");

  script_tag(name:"affected", value:"All Editions of Avast Antivirus before version 19.8.");

  script_tag(name:"solution", value:"Update to Avast Antivirus version 19.8 or later.");

  script_xref(name:"URL", value:"https://safebreach.com/Post/Avast-Antivirus-AVG-Antivirus-DLL-Preloading-into-PPL-and-Potential-Abuses");

  exit(0);
}

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

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

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

if( version_is_less( version:vers, test_version:"19.8" ) ) {
  report = report_fixed_ver( installed_version:vers, fixed_version:"19.8", install_path:path );
  security_message( data:report, port:0 );
  exit( 0 );
}

exit( 99 );