FKIE_CVE-2026-12249

Vulnerability from fkie_nvd - Published: 2026-06-22 18:16 - Updated: 2026-06-22 20:18
Severity
9.0 (Critical) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Summary
An issue was discovered in Canonical ADSys upstream versions through v0.16.2. During Active Directory Certificate Services (AD CS) certificate auto-enrollment via the vendored Samba client script (internal/policies/certificate/python/vendor_samba/gp/gp_cert_auto_enroll_ext.py), ADSys utilizes a plaintext HTTP connection (http://) instead of a secure HTTPS connection (https://) to request the CA certificate from the Active Directory Certificate Services server (GetCACert). An unauthenticated network attacker positioned between the managed Ubuntu host and the configured AD CS CA hostname can conduct a Man-in-the-Middle (MITM) attack. By intercepting the plaintext HTTP request, the attacker can supply an arbitrary, attacker-controlled Root CA certificate. Because the system automatically accepts this certificate and registers it into the local system trust store via update-ca-certificates, this results in system-wide trust store poisoning. Consequently, TLS clients utilizing the operating system trust store on the affected machine will accept rogue certificates for arbitrary domains, enabling persistent decryption and interception of subsequent TLS connections. This issue is resolved in version v0.16.3.
References
security@ubuntu.comhttps://github.com/ubuntu/adsys/commit/8b1939f96d3827b4426eb06c1ced5bf317b0a99d
security@ubuntu.comhttps://ubuntu.com/security/CVE-2026-12249
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "collectionURL": "https://github.com/ubuntu",
          "defaultStatus": "unaffected",
          "packageName": "adsys",
          "repo": "https://github.com/ubuntu/adsys",
          "versions": [
            {
              "lessThan": "0.16.3",
              "status": "affected",
              "version": "0.13.0",
              "versionType": "semver"
            }
          ]
        },
        {
          "collectionURL": "https://launchpad.net/ubuntu/focal",
          "defaultStatus": "unaffected",
          "packageName": "adsys",
          "platforms": [
            "Linux"
          ],
          "product": "Ubuntu 20.04 LTS",
          "repo": "https://launchpad.net/ubuntu/+source/adsys",
          "vendor": "Canonical",
          "versions": [
            {
              "status": "unaffected",
              "version": "0.9.2~20.04.2ubuntu0.1+esm2",
              "versionType": "dpkg"
            }
          ]
        },
        {
          "collectionURL": "https://launchpad.net/ubuntu/jammy",
          "defaultStatus": "affected",
          "packageName": "adsys",
          "platforms": [
            "Linux"
          ],
          "product": "Ubuntu 22.04 LTS",
          "repo": "https://launchpad.net/ubuntu/+source/adsys",
          "vendor": "Canonical",
          "versions": [
            {
              "status": "unaffected",
              "version": "0.16.3~22.04.2ubuntu0.22.04.1",
              "versionType": "dpkg"
            }
          ]
        },
        {
          "collectionURL": "https://launchpad.net/ubuntu/noble",
          "defaultStatus": "affected",
          "packageName": "adsys",
          "platforms": [
            "Linux"
          ],
          "product": "Ubuntu 24.04 LTS",
          "repo": "https://launchpad.net/ubuntu/+source/adsys",
          "vendor": "Canonical",
          "versions": [
            {
              "status": "unaffected",
              "version": "0.16.3~24.04.2ubuntu0.24.04.1",
              "versionType": "dpkg"
            }
          ]
        },
        {
          "collectionURL": "https://launchpad.net/ubuntu/questing",
          "defaultStatus": "unaffected",
          "packageName": "adsys",
          "platforms": [
            "Linux"
          ],
          "product": "Ubuntu 25.10",
          "repo": "https://launchpad.net/ubuntu/+source/adsys",
          "vendor": "Canonical",
          "versions": [
            {
              "status": "unaffected",
              "version": "0.16.3",
              "versionType": "dpkg"
            }
          ]
        },
        {
          "collectionURL": "https://launchpad.net/ubuntu/resolute",
          "defaultStatus": "unaffected",
          "packageName": "adsys",
          "platforms": [
            "Linux"
          ],
          "product": "Ubuntu 26.04 LTS",
          "repo": "https://launchpad.net/ubuntu/+source/adsys",
          "vendor": "Canonical",
          "versions": [
            {
              "status": "unaffected",
              "version": "0.16.4ubuntu1",
              "versionType": "dpkg"
            }
          ]
        }
      ],
      "source": "security@ubuntu.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "An issue was discovered in Canonical ADSys upstream versions through v0.16.2. During Active Directory Certificate Services (AD CS) certificate auto-enrollment via the vendored Samba client script (internal/policies/certificate/python/vendor_samba/gp/gp_cert_auto_enroll_ext.py), ADSys utilizes a plaintext HTTP connection (http://) instead of a secure HTTPS connection (https://) to request the CA certificate from the Active Directory Certificate Services server (GetCACert). An unauthenticated network attacker positioned between the managed Ubuntu host and the configured AD CS CA hostname can conduct a Man-in-the-Middle (MITM) attack. By intercepting the plaintext HTTP request, the attacker can supply an arbitrary, attacker-controlled Root CA certificate. Because the system automatically accepts this certificate and registers it into the local system trust store via update-ca-certificates, this results in system-wide trust store poisoning. Consequently, TLS clients utilizing the operating system trust store on the affected machine will accept rogue certificates for arbitrary domains, enabling persistent decryption and interception of subsequent TLS connections. This issue is resolved in version v0.16.3."
    }
  ],
  "id": "CVE-2026-12249",
  "lastModified": "2026-06-22T20:18:53.300",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.0,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.2,
        "impactScore": 6.0,
        "source": "security@ubuntu.com",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "YES",
          "Recovery": "IRRECOVERABLE",
          "Safety": "NEGLIGIBLE",
          "attackComplexity": "HIGH",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 9.0,
          "baseSeverity": "CRITICAL",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "PROOF_OF_CONCEPT",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "NONE",
          "providerUrgency": "RED",
          "subAvailabilityImpact": "HIGH",
          "subConfidentialityImpact": "HIGH",
          "subIntegrityImpact": "HIGH",
          "userInteraction": "NONE",
          "valueDensity": "DIFFUSE",
          "vectorString": "CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:N/AU:Y/R:I/V:D/RE:L/U:Red",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "LOW"
        },
        "source": "security@ubuntu.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-12249",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-06-22T17:30:38.451893Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-06-22T18:16:31.917",
  "references": [
    {
      "source": "security@ubuntu.com",
      "url": "https://github.com/ubuntu/adsys/commit/8b1939f96d3827b4426eb06c1ced5bf317b0a99d"
    },
    {
      "source": "security@ubuntu.com",
      "url": "https://ubuntu.com/security/CVE-2026-12249"
    }
  ],
  "sourceIdentifier": "security@ubuntu.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-348"
        }
      ],
      "source": "security@ubuntu.com",
      "type": "Secondary"
    }
  ]
}


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