GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

FKIE_CVE-2018-20784

Vulnerability from fkie_nvd - Published: 2019-02-22 15:29 - Updated: 2026-06-17 01:53
Severity
9.8 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Summary
In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq's, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load.
References
cve@mitre.orghttp://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c40f7d74c741a907cfaeb73a7697081881c497d0Patch, Vendor Advisory
cve@mitre.orghttps://access.redhat.com/errata/RHSA-2019:1959Third Party Advisory
cve@mitre.orghttps://access.redhat.com/errata/RHSA-2019:1971Third Party Advisory
cve@mitre.orghttps://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.2Release Notes, Vendor Advisory
cve@mitre.orghttps://github.com/torvalds/linux/commit/c40f7d74c741a907cfaeb73a7697081881c497d0Patch, Third Party Advisory
cve@mitre.orghttps://usn.ubuntu.com/4115-1/Third Party Advisory
cve@mitre.orghttps://usn.ubuntu.com/4118-1/Third Party Advisory
cve@mitre.orghttps://usn.ubuntu.com/4211-1/Third Party Advisory
cve@mitre.orghttps://usn.ubuntu.com/4211-2/Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c40f7d74c741a907cfaeb73a7697081881c497d0Patch, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://access.redhat.com/errata/RHSA-2019:1959Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://access.redhat.com/errata/RHSA-2019:1971Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.2Release Notes, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://github.com/torvalds/linux/commit/c40f7d74c741a907cfaeb73a7697081881c497d0Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://usn.ubuntu.com/4115-1/Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://usn.ubuntu.com/4118-1/Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://usn.ubuntu.com/4211-1/Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://usn.ubuntu.com/4211-2/Third Party Advisory
Impacted products
Vendor Product Version
linux linux_kernel *
linux linux_kernel *
linux linux_kernel *
linux linux_kernel 5.0
canonical ubuntu_linux 14.04
canonical ubuntu_linux 16.04
canonical ubuntu_linux 18.04
redhat enterprise_linux 8.0
redhat enterprise_linux_for_real_time 8
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "n/a",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "n/a"
            }
          ]
        }
      ],
      "source": "cve@mitre.org"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "8C6AA6D9-6073-4F71-8AF8-5F2828D88398",
              "versionEndExcluding": "4.14.93",
              "versionStartIncluding": "4.13",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "7E5568CD-D4BA-4C72-AC99-A0D2E7112EDD",
              "versionEndExcluding": "4.19.15",
              "versionStartIncluding": "4.19",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "22A4B1AF-0AE6-45BB-847A-470D03904BC4",
              "versionEndExcluding": "4.20.2",
              "versionStartIncluding": "4.20",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.0:rc1:*:*:*:*:*:*",
              "matchCriteriaId": "B5F099C8-DC7F-48C6-AAF8-C0DBFFD49620",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:canonical:ubuntu_linux:14.04:*:*:*:esm:*:*:*",
              "matchCriteriaId": "815D70A8-47D3-459C-A32C-9FEACA0659D1",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:canonical:ubuntu_linux:16.04:*:*:*:esm:*:*:*",
              "matchCriteriaId": "7A5301BF-1402-4BE0-A0F8-69FBE79BC6D6",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
              "matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*",
              "matchCriteriaId": "F4CFF558-3C47-480D-A2F0-BABF26042943",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:redhat:enterprise_linux_for_real_time:8:*:*:*:*:*:*:*",
              "matchCriteriaId": "CBF9BCF3-187F-410A-96CA-9C47D3ED6924",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel before 4.20.2, kernel/sched/fair.c mishandles leaf cfs_rq\u0027s, which allows attackers to cause a denial of service (infinite loop in update_blocked_averages) or possibly have unspecified other impact by inducing a high load."
    },
    {
      "lang": "es",
      "value": "En el kernel de Linux, en versiones anteriores a la 4.20.2, kernel/sched/fair.c gestiona leaf cfs_rq de manera incorrecta, lo que permite que los atacantes provoquen una denegaci\u00f3n de servicio (bucle infinito en update_blocked_averages) o, posiblemente, otro impacto sin especificar induciendo una carga alta."
    }
  ],
  "id": "CVE-2018-20784",
  "lastModified": "2026-06-17T01:53:28.050",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "HIGH",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "NETWORK",
          "authentication": "NONE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 7.5,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:N/AC:L/Au:N/C:P/I:P/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 10.0,
        "impactScore": 6.4,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 9.8,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.9,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2019-02-22T15:29:00.237",
  "references": [
    {
      "source": "cve@mitre.org",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "url": "http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c40f7d74c741a907cfaeb73a7697081881c497d0"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://access.redhat.com/errata/RHSA-2019:1959"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://access.redhat.com/errata/RHSA-2019:1971"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Release Notes",
        "Vendor Advisory"
      ],
      "url": "https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.2"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/torvalds/linux/commit/c40f7d74c741a907cfaeb73a7697081881c497d0"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://usn.ubuntu.com/4115-1/"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://usn.ubuntu.com/4118-1/"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://usn.ubuntu.com/4211-1/"
    },
    {
      "source": "cve@mitre.org",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://usn.ubuntu.com/4211-2/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Vendor Advisory"
      ],
      "url": "http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=c40f7d74c741a907cfaeb73a7697081881c497d0"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://access.redhat.com/errata/RHSA-2019:1959"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://access.redhat.com/errata/RHSA-2019:1971"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Release Notes",
        "Vendor Advisory"
      ],
      "url": "https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.2"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://github.com/torvalds/linux/commit/c40f7d74c741a907cfaeb73a7697081881c497d0"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://usn.ubuntu.com/4115-1/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://usn.ubuntu.com/4118-1/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://usn.ubuntu.com/4211-1/"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://usn.ubuntu.com/4211-2/"
    }
  ],
  "sourceIdentifier": "cve@mitre.org",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-835"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

Sightings

Author Source Type Date Other

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.


Detection rules are retrieved from Rulezet.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.