CVE-2018-8171

Status: ModifiedHigh (7.5)—

A Security Feature Bypass vulnerability exists in ASP.NET when the number of incorrect login attempts is not validated, aka "ASP.NET Security Feature Bypass Vulnerability." This affects ASP.NET, ASP.NET Core 1.1, ASP.NET Core 1.0, ASP.NET Core 2.0, ASP.NET MVC 5.2.

CVSS

Version: 3.0
Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Base score: 7.5

Exploitation probability (EPSS)

Probability of exploitation in the next 30 days: 10%
Percentile among all scored CVEs: 96
Score date: 10/6/2026

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (3)

Microsoft — Asp.net Core Microsoft — Asp.net Model View Controller Microsoft — Asp.net Webpages

CWEs

CWE-287

References

Raw JSON (NVD)

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{
  "id": "CVE-2018-8171",
  "cveTags": [],
  "metrics": {
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        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 5,
          "accessVector": "NETWORK",
          "vectorString": "AV:N/AC:L/Au:N/C:N/I:P/A:N",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "LOW",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "NONE"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 10,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
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    "cvssMetricV30": [
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          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "NONE",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
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  "affected": [
    {
      "source": "secure@microsoft.com",
      "affectedData": [
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          "vendor": "Microsoft",
          "product": "ASP.NET",
          "versions": [
            {
              "status": "affected",
              "version": "Web Pages 3.2.3 on Microsoft Visual Studio 2013 Update 5"
            },
            {
              "status": "affected",
              "version": "Web Pages 3.2.3 on Microsoft Visual Studio 2015 Update 3"
            }
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        {
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              "status": "affected",
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              "version": "2.0"
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              "version": "Microsoft Visual Studio 2013 Update 5"
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  ],
  "published": "2018-07-11T00:29:00.320",
  "references": [
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      "tags": [
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        "VDB Entry"
      ],
      "source": "secure@microsoft.com"
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    {
      "url": "http://www.securitytracker.com/id/1041267",
      "tags": [
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        "VDB Entry"
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      "source": "secure@microsoft.com"
    },
    {
      "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8171",
      "tags": [
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        "Vendor Advisory"
      ],
      "source": "secure@microsoft.com"
    },
    {
      "url": "http://www.securityfocus.com/bid/104659",
      "tags": [
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        "VDB Entry"
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
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    {
      "url": "http://www.securitytracker.com/id/1041267",
      "tags": [
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        "VDB Entry"
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      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8171",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-287"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A Security Feature Bypass vulnerability exists in ASP.NET when the number of incorrect login attempts is not validated, aka \"ASP.NET Security Feature Bypass Vulnerability.\" This affects ASP.NET, ASP.NET Core 1.1, ASP.NET Core 1.0, ASP.NET Core 2.0, ASP.NET MVC 5.2."
    },
    {
      "lang": "es",
      "value": "Existe una vulnerabilidad de omisión de la característica de seguridad en ASP.NET cuando el número de intentos de inicio de sesión incorrectos no se valida. Esto también se conoce como \"ASP.NET Security Feature Bypass Vulnerability\". Esto afecta a ASP.NET, ASP.NET Core 1.1, ASP.NET Core 1.0, ASP.NET Core 2.0 y ASP.NET MVC 5.2."
    }
  ],
  "lastModified": "2026-06-17T02:04:23.840",
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            },
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              "matchCriteriaId": "E601B5A5-E15B-43BD-98D7-20CBF28A55C6"
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  "sourceIdentifier": "secure@microsoft.com"
}