Erlang/OTP (Erlang OTP) Httpd CGI Scripts Environment Variable Pollution Vulnerability (Sep 2025, httpoxy) - Linux

# 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("1.3.6.1.4.1.25623.1.0.119093");
  script_version("2025-09-12T05:38:45+0000");
  script_tag(name:"last_modification", value:"2025-09-12 05:38:45 +0000 (Fri, 12 Sep 2025)");
  script_tag(name:"creation_date", value:"2025-09-11 14:22:32 +0000 (Thu, 11 Sep 2025)");
  script_tag(name:"cvss_base", value:"5.8");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:M/Au:N/C:P/I:P/A:N");
  script_tag(name:"severity_vector", value:"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2019-12-19 17:57:35 +0000 (Thu, 19 Dec 2019)");
  script_cve_id("CVE-2016-1000107");
  script_name("Erlang/OTP (Erlang OTP) Httpd CGI Scripts Environment Variable Pollution Vulnerability (Sep 2025, httpoxy) - Linux");
  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2025 Greenbone AG");
  script_family("General");
  script_dependencies("gb_erlang_otp_ssh_banner_detect.nasl", "os_detection.nasl");
  script_mandatory_keys("erlang/otp/detected", "Host/runs_unixoide");

  script_xref(name:"URL", value:"https://github.com/erlang/otp/security/advisories/GHSA-wrj5-4mmp-gvr8");

  script_tag(name:"summary", value:"Erlang/OTP (Erlang OTP) is prone to a Httpd CGI scripts
  environment variable pollution vulnerability in the inets component dubbed 'httpoxy'.");

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

  script_tag(name:"impact", value:"Httpd follows RFC 3875 section 4.1.18 and therefore does not
  protect applications from the presence of untrusted client data in the HTTP_PROXY environment
  variable, which might allow remote attackers to redirect an application's outbound HTTP traffic to
  an arbitrary proxy server via a crafted Proxy header in an HTTP request.");

  script_tag(name:"affected", value:"Erlang/OTP (Erlang OTP) versions prior to 26.2.5.15, 27.x prior
  to 27.3.4.3 and 28.x prior to 28.0.4.

  Note: While the advisory initially states that versions >= 17.0 are affected it also include
  the following note:

  > In the case of this vulnerability, versions prior to OTP 17.0 are likely also affected.");

  script_tag(name:"solution", value:"Update to version 26.2.5.15, 27.3.4.3, 28.0.4 or later.");

  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:"26.2.5.15" ) ) {
  report = report_fixed_ver( installed_version:version, fixed_version:"26.2.5.15", install_path:location );
  security_message( port:port, data:report );
  exit( 0 );
}

if( version_in_range_exclusive( version:version, test_version_lo:"27.0", test_version_up:"27.3.4.3" ) ) {
  report = report_fixed_ver( installed_version:version, fixed_version:"27.3.4.3", install_path:location );
  security_message( port:port, data:report );
  exit( 0 );
}

if( version_in_range_exclusive( version:version, test_version_lo:"28.0", test_version_up:"28.0.4" ) ) {
  report = report_fixed_ver( installed_version:version, fixed_version:"28.0.4", install_path:location );
  security_message( port:port, data:report );
  exit( 0 );
}

exit( 99 );