Erlang/OTP (Erlang OTP) < 23.2.3 Privilege Escalation Vulnerability

# SPDX-FileCopyrightText: 2025 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:erlang:erlang%2fotp";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.119107");
  script_version("2025-09-16T05:38:45+0000");
  script_tag(name:"last_modification", value:"2025-09-16 05:38:45 +0000 (Tue, 16 Sep 2025)");
  script_tag(name:"creation_date", value:"2025-09-15 13:03:57 +0000 (Mon, 15 Sep 2025)");
  script_tag(name:"cvss_base", value:"6.2");
  script_tag(name:"cvss_base_vector", value:"AV:L/AC:H/Au:N/C:C/I:C/A:C");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:L/AC:H/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:"2021-04-20 18:00:21 +0000 (Tue, 20 Apr 2021)");
  script_cve_id("CVE-2021-29221");
  script_name("Erlang/OTP (Erlang OTP) < 23.2.3 Privilege Escalation Vulnerability");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2025 Greenbone AG");
  script_family("Privilege escalation");
  script_dependencies("gb_erlang_otp_ssh_banner_detect.nasl", "os_detection.nasl");
  script_mandatory_keys("erlang/otp/detected", "Host/runs_windows");

  script_xref(name:"URL", value:"https://github.com/erlang/otp/releases/tag/OTP-23.2.3");
  script_xref(name:"URL", value:"https://www.attackiq.com/2021/04/04/dsa-lpe-erlang-win/");

  script_tag(name:"summary", value:"Erlang/OTP (Erlang OTP) is prone to a local privilege escalation
  vulnerability in the erts component.");

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

  script_tag(name:"impact", value:"By adding files to an existing installation's directory, a local
  attacker could hijack accounts of other users running Erlang programs or possibly coerce a service
  running with 'erlsrv.exe' to execute arbitrary code as Local System.");

  script_tag(name:"affected", value:"Erlang/OTP (Erlang OTP) versions prior to 23.2.3.

  Note: This can occur only under specific conditions on Windows with unsafe filesystem permissions.");

  script_tag(name:"solution", value:"Update to version 23.2.3 or later.");

  # nb: Only quite specific conditions needs to be fulfilled for being affected.
  script_tag(name:"qod_type", value:"remote_banner_unreliable");
  script_tag(name:"solution_type", value:"VendorFix");

  exit(0);
}

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

if( isnull( port = get_app_port( cpe:CPE ) ) )
  exit( 0 );

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

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

if( version_is_less( version:version, test_version:"23.2.3" ) ) {
  report = report_fixed_ver( installed_version:version, fixed_version:"23.2.3", install_path:location );
  security_message( port:port, data:report );
  exit( 0 );
}

exit( 99 );