Microsoft ASP.NET Core Security Feature Bypass (October 2025)

#%NASL_MIN_LEVEL 80900
##
# (C) Tenable, Inc. 
##

include('compat.inc');

if (description)
{
  script_id(270707);
  script_version("1.3");
  script_set_attribute(attribute:"plugin_modification_date", value:"2026/05/19");

  script_cve_id("CVE-2025-55315");
  script_xref(name:"IAVA", value:"2025-A-0753-S");

  script_name(english:"Microsoft ASP.NET Core Security Feature Bypass (October 2025)");

  script_set_attribute(attribute:"synopsis", value:
"The remote Windows host is affected by a security feature bypass vulnerability.");
  script_set_attribute(attribute:"description", value:
"The version of ASP.NET Core installed on the remote Windows host is 8.0.x prior to 8.0.21, 9.0.x prior to
9.0.10, or 10.0.0-rc.1.25451.107. It is, therefore, affected by a security feature bypass vulnerability.
Inconsistent interpretation of http requests ('http request/response smuggling') in ASP.NET Core allows an
authorized attacker to bypass a security feature over a network.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version
number.");
  script_set_attribute(attribute:"see_also", value:"https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-55315");
  script_set_attribute(attribute:"see_also", value:"https://github.com/dotnet/aspnetcore/issues/64033");
  script_set_attribute(attribute:"solution", value:
"Update .NET Core to version 8.0.21, 9.0.10, 10.0.0-rc.2.25502.107 or later.");
  script_set_cvss_base_vector("CVSS2#AV:N/AC:L/Au:S/C:C/I:C/A:P");
  script_set_cvss3_base_vector("CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L");
  script_set_attribute(attribute:"cvss_score_source", value:"CVE-2025-55315");

  script_set_attribute(attribute:"vuln_publication_date", value:"2025/10/14");
  script_set_attribute(attribute:"patch_publication_date", value:"2025/10/14");
  script_set_attribute(attribute:"plugin_publication_date", value:"2025/10/17");

  script_set_attribute(attribute:"plugin_type", value:"local");
  script_set_attribute(attribute:"cpe", value:"cpe:/a:microsoft:asp.net_core");
  script_set_attribute(attribute:"stig_severity", value:"I");
  script_end_attributes();

  script_category(ACT_GATHER_INFO);
  script_family(english:"Windows : Microsoft Bulletins");

  script_copyright(english:"This script is Copyright (C) 2025-2026 and is owned by Tenable, Inc. or an Affiliate thereof.");

  script_dependencies("microsoft_asp_dotnet_core_win.nbin");
  script_require_keys("SMB/Registry/Enumerated", "installed_sw/ASP .NET Core Windows");

  exit(0);
}

include('vdf.inc');

# @tvdl-content
var vuln_data = {
  'metadata': {'spec_version': '1.0'},
  'checks': [
    {
      'check_algorithm': 'default',
      'product': {'name': 'ASP .NET Core Windows', 'type': 'app'},
      'constraints': [
        {'min_version': '8.0',  'fixed_version': '8.0.21'},
        {'min_version': '9.0',  'fixed_version': '9.0.10'},
        {'equal': '10.0.0-rc.1.25451.107',  'fixed_version': '10.0.0-rc.2.25502.107'}
      ]
    }
  ]
};

var result = vdf::check_and_report(vuln_data:vuln_data, severity:SECURITY_HOLE);
vdf::handle_check_and_report_errors(vdf_result:result);