{
  "document": {
    "acknowledgments": [
      {
        "names": [
          "Sid"
        ]
      }
    ],
    "aggregate_severity": {
      "namespace": "https://www.microsoft.com/en-us/msrc/security-update-severity-rating-system",
      "text": "Important"
    },
    "category": "csaf_security_advisory",
    "csaf_version": "2.0",
    "distribution": {
      "text": "Public",
      "tlp": {
        "label": "WHITE",
        "url": "https://www.first.org/tlp/"
      }
    },
    "lang": "en-US",
    "notes": [
      {
        "category": "general",
        "text": "To determine the support lifecycle for your software, see the Microsoft Support Lifecycle: https://support.microsoft.com/lifecycle",
        "title": "Additional Resources"
      },
      {
        "category": "legal_disclaimer",
        "text": "The information provided in the Microsoft Knowledge Base is provided \\\"as is\\\" without warranty of any kind. Microsoft disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose. In no event shall Microsoft Corporation or its suppliers be liable for any damages whatsoever including direct, indirect, incidental, consequential, loss of business profits or special damages, even if Microsoft Corporation or its suppliers have been advised of the possibility of such damages. Some states do not allow the exclusion or limitation of liability for consequential or incidental damages so the foregoing limitation may not apply.",
        "title": "Disclaimer"
      },
      {
        "category": "general",
        "text": "Required. The vulnerability documented by this CVE requires customer action to resolve.",
        "title": "Customer Action"
      }
    ],
    "publisher": {
      "category": "vendor",
      "contact_details": "secure@microsoft.com",
      "name": "Microsoft Security Response Center",
      "namespace": "https://msrc.microsoft.com"
    },
    "references": [
      {
        "category": "self",
        "summary": "CVE-2025-55315 ASP.NET Security Feature Bypass Vulnerability - HTML",
        "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-55315"
      },
      {
        "category": "self",
        "summary": "CVE-2025-55315 ASP.NET Security Feature Bypass Vulnerability - CSAF",
        "url": "https://msrc.microsoft.com/csaf/advisories/2025/msrc_cve-2025-55315.json"
      },
      {
        "category": "external",
        "summary": "Microsoft Exploitability Index",
        "url": "https://www.microsoft.com/en-us/msrc/exploitability-index?rtc=1"
      },
      {
        "category": "external",
        "summary": "Microsoft Support Lifecycle",
        "url": "https://support.microsoft.com/lifecycle"
      },
      {
        "category": "external",
        "summary": "Common Vulnerability Scoring System",
        "url": "https://www.first.org/cvss"
      }
    ],
    "title": "ASP.NET Security Feature Bypass Vulnerability",
    "tracking": {
      "current_release_date": "2025-10-22T07:00:00.000Z",
      "generator": {
        "date": "2025-10-24T00:59:44.167Z",
        "engine": {
          "name": "MSRC Generator",
          "version": "1.0"
        }
      },
      "id": "msrc_CVE-2025-55315",
      "initial_release_date": "2025-10-14T07:00:00.000Z",
      "revision_history": [
        {
          "date": "2025-10-14T07:00:00.000Z",
          "legacy_version": "1",
          "number": "1",
          "summary": "Information published."
        },
        {
          "date": "2025-10-22T07:00:00.000Z",
          "legacy_version": "1.1",
          "number": "2",
          "summary": "Added an FAQ to explain the disparity between the Important severity, the exploitability assessment of \"less likely to be exploited\", and the high CVSS3.1 score of 9.9 out of 10."
        }
      ],
      "status": "final",
      "version": "2"
    }
  },
  "product_tree": {
    "branches": [
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c8.0.21",
            "product": {
              "name": "ASP.NET Core 8.0 \u003c8.0.21",
              "product_id": "6"
            }
          },
          {
            "category": "product_version",
            "name": "8.0.21",
            "product": {
              "name": "ASP.NET Core 8.0 8.0.21",
              "product_id": "12256"
            }
          }
        ],
        "category": "product_name",
        "name": "ASP.NET Core 8.0"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c9.0.10",
            "product": {
              "name": "ASP.NET Core 9.0 \u003c9.0.10",
              "product_id": "3"
            }
          },
          {
            "category": "product_version",
            "name": "9.0.10",
            "product": {
              "name": "ASP.NET Core 9.0 9.0.10",
              "product_id": "12507"
            }
          }
        ],
        "category": "product_name",
        "name": "ASP.NET Core 9.0"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c2.3.6",
            "product": {
              "name": "ASP.NET Core 2.3 \u003c2.3.6",
              "product_id": "1"
            }
          },
          {
            "category": "product_version",
            "name": "2.3.6",
            "product": {
              "name": "ASP.NET Core 2.3 2.3.6",
              "product_id": "20518"
            }
          }
        ],
        "category": "product_name",
        "name": "ASP.NET Core 2.3"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c17.12.13",
            "product": {
              "name": "Microsoft Visual Studio 2022 version 17.12 \u003c17.12.13",
              "product_id": "4"
            }
          },
          {
            "category": "product_version",
            "name": "17.12.13",
            "product": {
              "name": "Microsoft Visual Studio 2022 version 17.12 17.12.13",
              "product_id": "12459"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Visual Studio 2022 version 17.12"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c17.10.20",
            "product": {
              "name": "Microsoft Visual Studio 2022 version 17.10 \u003c17.10.20",
              "product_id": "5"
            }
          },
          {
            "category": "product_version",
            "name": "17.10.20",
            "product": {
              "name": "Microsoft Visual Studio 2022 version 17.10 17.10.20",
              "product_id": "12322"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Visual Studio 2022 version 17.10"
      },
      {
        "branches": [
          {
            "category": "product_version_range",
            "name": "\u003c17.14.17",
            "product": {
              "name": "Microsoft Visual Studio 2022 version 17.14 \u003c17.14.17",
              "product_id": "2"
            }
          },
          {
            "category": "product_version",
            "name": "17.14.17",
            "product": {
              "name": "Microsoft Visual Studio 2022 version 17.14 17.14.17",
              "product_id": "16767"
            }
          }
        ],
        "category": "product_name",
        "name": "Microsoft Visual Studio 2022 version 17.14"
      }
    ]
  },
  "vulnerabilities": [
    {
      "cve": "CVE-2025-55315",
      "cwe": {
        "id": "CWE-444",
        "name": "Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)"
      },
      "notes": [
        {
          "category": "general",
          "text": "Microsoft",
          "title": "Assigning CNA"
        },
        {
          "category": "faq",
          "text": "An authenticated attacker could exploit the vulnerability by sending a malicious http request to the web server.",
          "title": "How could an attacker exploit the vulnerability?"
        },
        {
          "category": "faq",
          "text": "An attacker who successfully exploited this vulnerability could view sensitive information such as other user\u0027s credentials (Confidentiality) and make changes to file contents on the target server (Integrity), and they might be able to force a crash within the server (Availability).",
          "title": "According to the CVSS metrics, successful exploitation of this vulnerability could lead to a high loss of confidentiality (C:H), and integrity (I:H) and some loss of availability (A:L). What does that mean for this vulnerability?"
        },
        {
          "category": "faq",
          "text": "If you are running .NET 8 or later install the .NET update from Microsoft Update, then restart your application or reboot the machine., If you are running .NET 2.3 you must update the package reference for Microsoft.AspNet.Server.Kestrel.Core to 2.3.6, then recompile your application and redeploy., If you are running a self-contained/single-file application, install the .NET update, recompile your application and redeploy.",
          "title": "What should I do to make sure my ASP.NET Core application is protected?"
        },
        {
          "category": "faq",
          "text": "An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.",
          "title": "According to the CVSS metric, a successful exploitation could lead to a scope change (S:C). What does this mean for this vulnerability?"
        },
        {
          "category": "faq",
          "text": "An attacker who successfully exploited this vulnerability could smuggle another HTTP request and bypass front-end security controls or hijack other users\u0027 credentials.",
          "title": "What kind of security feature could be bypassed by successfully exploiting this vulnerability?"
        },
        {
          "category": "faq",
          "text": "ASP.NET Core is a framework. CVSS scores applications. This mismatch makes scoring ASP.NET challenging. In situations like this, it is Microsoft\u0027s standard practice to score the worst possible case scenario for any application written using ASP.NET Core. \u0026quot;Exploitation less likely\u0026quot; refers to a more typical application which doesn\u0027t go outside the typical ASP.NET Core uses.\nThe vulnerability in ASP.NET Core allows HTTP request smuggling. This is a security feature bypass that can affect how your application enforces authentication, authorization, and other critical security checks. The vulnerability allows attackers to craft a request that hides another request inside it. Depending on how your app processes requests, this could lead to:\nElevation of privilege (EOP) \u2014 impersonating another user, Server-side request forgery (SSRF) \u2014 making internal requests, Cross-site request forgery (CSRF) bypass, Injection attacks \u2014 bypassing input validation\nThese are serious risks, especially for applications handling sensitive data or operating in regulated environments.\nWhile not every app is vulnerable, the scoring reflects the worst-case scenario\u2014a standard practice in CVSS to ensure customers take action.",
          "title": "This vulnerability is rated as an Important, Security Feature Bypass that is less likely to be exploited. Why is the CVSS score 9.9 out of 10?"
        }
      ],
      "product_status": {
        "fixed": [
          "12256",
          "12322",
          "12459",
          "12507",
          "16767",
          "20518"
        ],
        "known_affected": [
          "1",
          "2",
          "3",
          "4",
          "5",
          "6"
        ]
      },
      "references": [
        {
          "category": "self",
          "summary": "CVE-2025-55315 ASP.NET Security Feature Bypass Vulnerability - HTML",
          "url": "https://msrc.microsoft.com/update-guide/vulnerability/CVE-2025-55315"
        },
        {
          "category": "self",
          "summary": "CVE-2025-55315 ASP.NET Security Feature Bypass Vulnerability - CSAF",
          "url": "https://msrc.microsoft.com/csaf/advisories/2025/msrc_cve-2025-55315.json"
        }
      ],
      "remediations": [
        {
          "category": "vendor_fix",
          "date": "2025-10-14T07:00:00.000Z",
          "details": "8.0.21:Security Update:https://support.microsoft.com/help/5068331",
          "product_ids": [
            "6"
          ],
          "url": "https://support.microsoft.com/help/5068331"
        },
        {
          "category": "vendor_fix",
          "date": "2025-10-14T07:00:00.000Z",
          "details": "9.0.10:Security Update:https://support.microsoft.com/help/5068332",
          "product_ids": [
            "3"
          ],
          "url": "https://support.microsoft.com/help/5068332"
        },
        {
          "category": "vendor_fix",
          "date": "2025-10-14T07:00:00.000Z",
          "details": "2.3.6:Security Update:https://github.com/dotnet/aspnetcore/issues/64033",
          "product_ids": [
            "1"
          ],
          "url": "https://github.com/dotnet/aspnetcore/issues/64033"
        },
        {
          "category": "vendor_fix",
          "date": "2025-10-14T07:00:00.000Z",
          "details": "17.12.13:Security Update:https://learn.microsoft.com/en-us/visualstudio/releases/2022/release-notes",
          "product_ids": [
            "4"
          ],
          "url": "https://learn.microsoft.com/en-us/visualstudio/releases/2022/release-notes"
        },
        {
          "category": "vendor_fix",
          "date": "2025-10-14T07:00:00.000Z",
          "details": "17.10.20:Security Update:https://learn.microsoft.com/en-us/visualstudio/releases/2022/release-notes",
          "product_ids": [
            "5"
          ],
          "url": "https://learn.microsoft.com/en-us/visualstudio/releases/2022/release-notes"
        },
        {
          "category": "vendor_fix",
          "date": "2025-10-14T07:00:00.000Z",
          "details": "17.14.17:Security Update:https://learn.microsoft.com/en-us/visualstudio/releases/2022/release-notes",
          "product_ids": [
            "2"
          ],
          "url": "https://learn.microsoft.com/en-us/visualstudio/releases/2022/release-notes"
        }
      ],
      "scores": [
        {
          "cvss_v3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 9.9,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "environmentalsScore": 0.0,
            "exploitCodeMaturity": "UNPROVEN",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "remediationLevel": "OFFICIAL_FIX",
            "reportConfidence": "CONFIRMED",
            "scope": "CHANGED",
            "temporalScore": 8.6,
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:L/E:U/RL:O/RC:C",
            "version": "3.1"
          },
          "products": [
            "1",
            "2",
            "3",
            "4",
            "5",
            "6"
          ]
        }
      ],
      "threats": [
        {
          "category": "impact",
          "details": "Security Feature Bypass"
        },
        {
          "category": "exploit_status",
          "details": "Publicly Disclosed:No;Exploited:No;Latest Software Release:Exploitation Less Likely"
        }
      ],
      "title": "ASP.NET Security Feature Bypass Vulnerability"
    }
  ]
}