ASP.NET Core Denial of Service Vulnerability - Windows

# SPDX-FileCopyrightText: 2018 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:microsoft:asp.net_core";

if(description)
{
  script_oid("1.3.6.1.4.1.25623.1.0.813043");
  script_version("2025-09-17T05:39:26+0000");
  script_cve_id("CVE-2018-0875");
  script_tag(name:"cvss_base", value:"5.0");
  script_tag(name:"cvss_base_vector", value:"AV:N/AC:L/Au:N/C:N/I:N/A:P");
  script_tag(name:"last_modification", value:"2025-09-17 05:39:26 +0000 (Wed, 17 Sep 2025)");
  script_tag(name:"severity_vector", value:"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H");
  script_tag(name:"severity_origin", value:"NVD");
  script_tag(name:"severity_date", value:"2020-08-24 17:37:00 +0000 (Mon, 24 Aug 2020)");
  script_tag(name:"creation_date", value:"2018-03-16 11:09:04 +0530 (Fri, 16 Mar 2018)");
  script_name("ASP.NET Core Denial of Service Vulnerability - Windows");

  script_tag(name:"summary", value:"ASP.NET Core is prone to a denial of service (DoS) 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 in the way that .NET Core
  handles specially crafted requests, causing a hash collision.");

  script_tag(name:"impact", value:"Successful exploitation will allow an
  attacker to cause performance to degrade significantly enough to cause a
  denial of service condition.");

  script_tag(name:"affected", value:".NET Core 1.0.9 and prior, 1.1.x to 1.1.6, and 2.0.x to  2.0.5 and
  .NET Core SDK prior to versions 1.1.8, 2.1.x to 2.1.101.");

  script_tag(name:"solution", value:"Upgrade to .NET Core runtimes to versions
  1.0.10, 1.1.7 or 2.0.6 or later or upgrade to .NET Core SDK to versions 1.1.8
  or 2.1.101 or later.");

  script_tag(name:"solution_type", value:"VendorFix");
  script_tag(name:"qod_type", value:"registry");
  script_xref(name:"URL", value:"https://github.com/dotnet/announcements/issues/62");
  script_xref(name:"URL", value:"http://www.securityfocus.com/bid/103225");
  script_xref(name:"URL", value:"https://github.com/dotnet/core/blob/master/release-notes/2.1/2.1.0-preview1.md");

  script_category(ACT_GATHER_INFO);
  script_copyright("Copyright (C) 2018 Greenbone AG");
  script_family("Windows");
  script_dependencies("gb_asp_dotnet_core_detect_win.nasl");
  script_mandatory_keys("ASP.NET/Core/Ver");
  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);

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

if(!coreVers || coreVers !~ "^(1\.[01]|2\.0)")
  exit(0);

if(!corerunVer = get_kb_item(".NET/Core/Runtime/Ver")) {
  if(!codesdkVer = get_kb_item(".NET/Core/SDK/Ver")) {
    exit(0);
  }
}

if(corerunVer) {
  if(version_in_range(version:corerunVer, test_version:"1.0", test_version2:"1.0.9")) {
    fix = "1.0.10";
  }

  else if(version_in_range(version:corerunVer, test_version:"1.1", test_version2:"1.1.6")) {
    fix = "1.1.7";
  }

  else if(version_in_range(version:corerunVer, test_version:"2.0", test_version2:"2.0.5")) {
    fix = "2.0.6";
  }
}

else if(codesdkVer) {
  if(version_in_range(version:codesdkVer, test_version:"1.1", test_version2:"1.1.7")) {
    fix1 = "1.1.8";
  }

  else if(version_in_range(version:codesdkVer, test_version:"2.1", test_version2:"2.1.100")) {
    fix1 = "2.1.101";
  }
}

if(fix) {
  report = report_fixed_ver(installed_version:"ASP .NET Core With Microsoft .NET Core runtimes " + corerunVer,
                            fixed_version:"ASP .NET Core With Microsoft .NET Core runtimes version " + fix, install_path:path);
  security_message(port:0, data:report);
  exit(0);
}

else if(fix1) {
  report = report_fixed_ver(installed_version:"ASP .NET Core With Microsoft .NET Core SDK " + codesdkVer,
                            fixed_version:"ASP .NET Core With Microsoft .NET Core SDK version " + fix1, install_path:path);
  security_message(port:0, data:report);
  exit(0);
}

exit(99);