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CVE-2023-27496

Status: ModifiedHigh (7.5)—

Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, the OAuth filter assumes that a `state` query param is present on any response that looks like an OAuth redirect response. Sending it a request with the URI path equivalent to the redirect path, without the `state` parameter, will lead to abnormal termination of Envoy process. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 contain a patch. The issue can also be mitigated by locking down OAuth traffic, disabling the filter, or by filtering traffic before it reaches the OAuth filter (e.g. via a lua script).

CVSS

Exploitation probability (EPSS)

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 (1)

Envoyproxy — Envoy

CWEs

References

Raw JSON (NVD)

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{
  "id": "CVE-2023-27496",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2023-27496",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2025-02-10T21:34:11.044829Z"
        }
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Secondary",
        "source": "security-advisories@github.com",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 6.5,
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "REQUIRED",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 2.8
      },
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7.5,
          "attackVector": "NETWORK",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "LOW",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "confidentialityImpact": "NONE"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 3.9
      }
    ]
  },
  "affected": [
    {
      "source": "security-advisories@github.com",
      "affectedData": [
        {
          "vendor": "envoyproxy",
          "product": "envoy",
          "versions": [
            {
              "status": "affected",
              "version": ">= 1.25.0, < 1.25.3"
            },
            {
              "status": "affected",
              "version": ">= 1.24.0, < 1.24.4"
            },
            {
              "status": "affected",
              "version": ">= 1.23.0, < 1.23.6"
            },
            {
              "status": "affected",
              "version": "< 1.22.9"
            }
          ]
        }
      ]
    }
  ],
  "published": "2023-04-04T20:15:07.520",
  "references": [
    {
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-j79q-2g66-2xv5",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "source": "security-advisories@github.com"
    },
    {
      "url": "https://github.com/envoyproxy/envoy/security/advisories/GHSA-j79q-2g66-2xv5",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "security-advisories@github.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        }
      ]
    },
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "NVD-CWE-noinfo"
        }
      ]
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  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "Envoy is an open source edge and service proxy designed for cloud-native applications. Prior to versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9, the OAuth filter assumes that a `state` query param is present on any response that looks like an OAuth redirect response. Sending it a request with the URI path equivalent to the redirect path, without the `state` parameter, will lead to abnormal termination of Envoy process. Versions 1.26.0, 1.25.3, 1.24.4, 1.23.6, and 1.22.9 contain a patch. The issue can also be mitigated by locking down OAuth traffic, disabling the filter, or by filtering traffic before it reaches the OAuth filter (e.g. via a lua script). \n"
    }
  ],
  "lastModified": "2026-06-17T05:45:20.163",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "DAD93214-C958-4A69-9291-15D1C22CFD3F",
              "versionEndExcluding": "1.22.9"
            },
            {
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "17BFB303-DA5A-4E83-93F7-3C1EA340E434",
              "versionEndExcluding": "1.23.6",
              "versionStartIncluding": "1.23.0"
            },
            {
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "92B633B8-FA4A-4630-9302-96F2C8336E36",
              "versionEndExcluding": "1.24.4",
              "versionStartIncluding": "1.24.0"
            },
            {
              "criteria": "cpe:2.3:a:envoyproxy:envoy:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "8AFC6741-6FDF-47F6-A4AF-B5F5233ABB71",
              "versionEndExcluding": "1.25.3",
              "versionStartIncluding": "1.25.0"
            }
          ],
          "operator": "OR"
        }
      ]
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  ],
  "sourceIdentifier": "security-advisories@github.com"
}