« Back to list

CVE-2020-25656

Status: ModifiedMedium (4.1)—

A flaw was found in the Linux kernel. A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality.

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 (4)

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2020-25656",
  "cveTags": [],
  "metrics": {
    "cvssMetricV2": [
      {
        "type": "Primary",
        "source": "nvd@nist.gov",
        "cvssData": {
          "version": "2.0",
          "baseScore": 1.9,
          "accessVector": "LOCAL",
          "vectorString": "AV:L/AC:M/Au:N/C:P/I:N/A:N",
          "authentication": "NONE",
          "integrityImpact": "NONE",
          "accessComplexity": "MEDIUM",
          "availabilityImpact": "NONE",
          "confidentialityImpact": "PARTIAL"
        },
        "acInsufInfo": false,
        "impactScore": 2.9,
        "baseSeverity": "LOW",
        "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": 4.1,
          "attackVector": "LOCAL",
          "baseSeverity": "MEDIUM",
          "vectorString": "CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:N/A:N",
          "integrityImpact": "NONE",
          "userInteraction": "NONE",
          "attackComplexity": "HIGH",
          "availabilityImpact": "NONE",
          "privilegesRequired": "HIGH",
          "confidentialityImpact": "HIGH"
        },
        "impactScore": 3.6,
        "exploitabilityScore": 0.5
      }
    ]
  },
  "affected": [
    {
      "source": "secalert@redhat.com",
      "affectedData": [
        {
          "vendor": "n/a",
          "product": "kernel",
          "versions": [
            {
              "status": "affected",
              "version": "kernel 5.10-rc2"
            }
          ]
        }
      ]
    }
  ],
  "published": "2020-12-02T01:15:12.607",
  "references": [
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1888726",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Patch",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://lkml.org/lkml/2020/10/16/84",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://lkml.org/lkml/2020/10/29/528",
      "tags": [
        "Mailing List",
        "Patch",
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://www.starwindsoftware.com/security/sw-20210325-0006/",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "secalert@redhat.com"
    },
    {
      "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1888726",
      "tags": [
        "Exploit",
        "Issue Tracking",
        "Patch",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00015.html",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lists.debian.org/debian-lts-announce/2020/12/msg00027.html",
      "tags": [
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lkml.org/lkml/2020/10/16/84",
      "tags": [
        "Exploit",
        "Mailing List",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://lkml.org/lkml/2020/10/29/528",
      "tags": [
        "Mailing List",
        "Patch",
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    },
    {
      "url": "https://www.starwindsoftware.com/security/sw-20210325-0006/",
      "tags": [
        "Third Party Advisory"
      ],
      "source": "af854a3a-2127-422b-91ae-364da2661108"
    }
  ],
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "secalert@redhat.com",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    },
    {
      "type": "Secondary",
      "source": "nvd@nist.gov",
      "description": [
        {
          "lang": "en",
          "value": "CWE-416"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "A flaw was found in the Linux kernel. A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality."
    },
    {
      "lang": "es",
      "value": "Se encontró un fallo en el kernel de Linux. Se encontró un uso de la memoria previamente liberada en la manera en que el subsistema de la consola estaba usando ioctls KDGKBSENT y KDSKBSENT. Un usuario local podría usar este fallo para obtener acceso a la memoria de lectura fuera de los límites. La mayor amenaza de esta vulnerabilidad es la confidencialidad de los datos"
    }
  ],
  "lastModified": "2026-06-17T03:07:04.270",
  "configurations": [
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "D61CA62B-157A-4415-B8FD-7C3C1208315D",
              "versionEndExcluding": "5.10"
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.10:rc1:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "9DD7EB1D-064C-4DB9-AD34-D8EF78312C17"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "142AD0DD-4CF3-4D74-9442-459CE3347E3A"
            },
            {
              "criteria": "cpe:2.3:o:redhat:enterprise_linux:8.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F4CFF558-3C47-480D-A2F0-BABF26042943"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
              "vulnerable": true,
              "matchCriteriaId": "DEECE5FC-CACF-4496-A3E7-164736409252"
            }
          ],
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "negate": false,
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build12533:*:*:*:vsphere:*:*",
              "vulnerable": true,
              "matchCriteriaId": "0E5C2815-65C8-48D7-BF31-6104EDD0CBE5"
            },
            {
              "criteria": "cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build12658:*:*:*:vsphere:*:*",
              "vulnerable": true,
              "matchCriteriaId": "6FF4A265-AFFD-4853-B3CE-A55E950E8B5B"
            },
            {
              "criteria": "cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build12859:*:*:*:vsphere:*:*",
              "vulnerable": true,
              "matchCriteriaId": "E6484296-5BA8-408A-A087-A0D86BA50703"
            },
            {
              "criteria": "cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build13170:*:*:*:vsphere:*:*",
              "vulnerable": true,
              "matchCriteriaId": "5D31D4A3-7D1E-472F-9BB6-AF889DA7C763"
            },
            {
              "criteria": "cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build13586:*:*:*:vsphere:*:*",
              "vulnerable": true,
              "matchCriteriaId": "F67B6B43-FF39-4B05-8704-EDFCED4117E6"
            },
            {
              "criteria": "cpe:2.3:a:starwindsoftware:starwind_virtual_san:v8:build13861:*:*:*:vsphere:*:*",
              "vulnerable": true,
              "matchCriteriaId": "C79FA879-7855-467B-A98D-7D914940F9D3"
            }
          ],
          "operator": "OR"
        }
      ]
    }
  ],
  "sourceIdentifier": "secalert@redhat.com"
}