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CVE-2018-6557

Estado: ModificadaAlta (7)—

The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files. A local attacker could use this issue to cause a denial of service, or possibly escalate privileges if kernel symlink restrictions were disabled.

CVSS

Probabilidad de explotación (EPSS)

EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).

Tecnologías afectadas (2)

Base-files Project — Base-filesCanonical — Ubuntu Linux

CWE

Referencias

JSON original (NVD)

Mostrar
{
  "id": "CVE-2018-6557",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 4.4,
          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:M/Au:N/C:P/I:P/A:P",
          "authentication": "NONE",
          "integrityImpact": "PARTIAL",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "PARTIAL",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 6.4,
        "baseSeverity": "MEDIUM",
        "obtainAllPrivilege": false,
        "exploitabilityScore": 3.4,
        "obtainUserPrivilege": false,
        "obtainOtherPrivilege": false,
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "scope": "UNCHANGED",
          "version": "3.1",
          "baseScore": 7,
          "attackVector": "LOCAL",
          "baseSeverity": "HIGH",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "integrityImpact": "HIGH",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 5.9,
        "exploitabilityScore": 1
      }
    ]
  },
  "affected": [
    {
      "source": "security@ubuntu.com",
      "affectedData": [
        {
          "vendor": "Ubuntu",
          "product": "base-files",
          "versions": [
            {
              "status": "affected",
              "version": "unspecified",
              "lessThan": "10.1ubuntu2.2",
              "versionType": "custom"
            }
          ]
        }
      ]
    }
  ],
  "published": "2018-08-21T16:29:00.637",
  "references": [
    {
      "url": "http://www.securityfocus.com/bid/105148",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ],
      "source": "security@ubuntu.com"
    },
    {
      "url": "http://www.securitytracker.com/id/1041530",
      "tags": [
        "Broken Link",
        "Third Party Advisory",
        "VDB Entry"
      ],
      "source": "security@ubuntu.com"
    },
    {
      "url": "https://usn.ubuntu.com/3748-1/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "security@ubuntu.com"
    },
    {
      "url": "http://www.securityfocus.com/bid/105148",
      "tags": [
        "Third Party Advisory",
        "VDB Entry"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "http://www.securitytracker.com/id/1041530",
      "tags": [
        "Broken Link",
        "Third Party Advisory",
        "VDB Entry"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://usn.ubuntu.com/3748-1/",
      "tags": [
        "Vendor Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Primary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-59"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "The MOTD update script in the base-files package in Ubuntu 18.04 LTS before 10.1ubuntu2.2, and Ubuntu 18.10 before 10.1ubuntu6 incorrectly handled temporary files. A local attacker could use this issue to cause a denial of service, or possibly escalate privileges if kernel symlink restrictions were disabled."
    },
    {
      "lang": "es",
      "value": "El script de actualización de MOTD en el paquete de archivos base en Ubuntu 18.04 LTS en versiones anteriores a la 10.1ubuntu2.2 y Ubuntu 18.10 anteriores a la 10.1ubuntu6 manejaba incorrectamente los archivos temporales. Un atacante local podría usar este problema para provocar una denegación de servicio o posiblemente escalar privilegios si se desactivan las restricciones de enlaces simbólicos del kernel."
    }
  ],
  "lastModified": "2026-06-17T02:02:01.367",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:base-files_project:base-files:10.1ubuntu2.2:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "8A95C549-93EC-4A40-904F-7CFED2A94694"
            },
            {
              "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D"
            },
            {
              "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.10:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "07C312A0-CD2C-4B9C-B064-6409B25C278F"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "security@ubuntu.com"
}