FKIE_CVE-2026-70667

Vulnerability from fkie_nvd - Published: 2026-08-18 19:17 - Updated: 2026-08-19 16:18
Severity
6.3 (Medium) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L
Summary
Lemur manages TLS certificate creation. Prior to 1.9.3, _validate_revocation_url in lemur/certificates/verify.py checked the original CRL or OCSP URL but the later request could reach a different destination. The CRL requests.get call followed HTTP redirects without validating each Location target, so a public attacker-controlled URL could redirect to loopback, RFC1918, link-local, or instance-metadata addresses. Validation and connection also performed separate DNS resolutions, creating a time-of-check time-of-use window for DNS rebinding on both CRL and OCSP paths. An operator uploading a certificate through POST /api/1/certificates/upload could therefore induce blind internal requests despite the earlier mitigation. The fix disables redirects and pins validated addresses while preserving the correct Host value. This issue is fixed in version 1.9.3.
References
security-advisories@github.comhttps://github.com/Netflix/lemur/commit/ed504a830f38a83825b1570302e9f38d6553938a
security-advisories@github.comhttps://github.com/Netflix/lemur/releases/tag/v1.9.3
security-advisories@github.comhttps://github.com/Netflix/lemur/security/advisories/GHSA-f3qq-49m6-rw8f
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/Netflix/lemur/security/advisories/GHSA-54vg-pfh7-jq95
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "lemur",
          "vendor": "Netflix",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.9.3"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Lemur manages TLS certificate creation. Prior to 1.9.3, _validate_revocation_url in lemur/certificates/verify.py checked the original CRL or OCSP URL but the later request could reach a different destination. The CRL requests.get call followed HTTP redirects without validating each Location target, so a public attacker-controlled URL could redirect to loopback, RFC1918, link-local, or instance-metadata addresses. Validation and connection also performed separate DNS resolutions, creating a time-of-check time-of-use window for DNS rebinding on both CRL and OCSP paths. An operator uploading a certificate through POST /api/1/certificates/upload could therefore induce blind internal requests despite the earlier mitigation. The fix disables redirects and pins validated addresses while preserving the correct Host value. This issue is fixed in version 1.9.3."
    }
  ],
  "id": "CVE-2026-70667",
  "lastModified": "2026-08-19T16:18:58.827",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 6.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "LOW",
          "integrityImpact": "LOW",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 3.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-70667",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-08-19T15:16:23.054190Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-08-18T19:17:03.293",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Netflix/lemur/commit/ed504a830f38a83825b1570302e9f38d6553938a"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Netflix/lemur/releases/tag/v1.9.3"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/Netflix/lemur/security/advisories/GHSA-f3qq-49m6-rw8f"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "url": "https://github.com/Netflix/lemur/security/advisories/GHSA-54vg-pfh7-jq95"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Received",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-367"
        },
        {
          "lang": "en",
          "value": "CWE-918"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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