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FKIE_CVE-2021-3492

Vulnerability from fkie_nvd - Published: 2021-04-17 05:15 - Updated: 2026-06-17 04:05
Severity
8.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Summary
Shiftfs, an out-of-tree stacking file system included in Ubuntu Linux kernels, did not properly handle faults occurring during copy_from_user() correctly. These could lead to either a double-free situation or memory not being freed at all. An attacker could use this to cause a denial of service (kernel memory exhaustion) or gain privileges via executing arbitrary code. AKA ZDI-CAN-13562.
References
security@ubuntu.comhttp://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.htmlThird Party Advisory, VDB Entry
security@ubuntu.comhttps://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333Mailing List, Patch, Vendor Advisory
security@ubuntu.comhttps://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6Mailing List, Patch, Vendor Advisory
security@ubuntu.comhttps://ubuntu.com/security/notices/USN-4917-1Vendor Advisory
security@ubuntu.comhttps://www.openwall.com/lists/oss-security/2021/04/16/2Mailing List, Third Party Advisory
security@ubuntu.comhttps://www.zerodayinitiative.com/advisories/ZDI-21-422/Third Party Advisory, VDB Entry
af854a3a-2127-422b-91ae-364da2661108http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.htmlThird Party Advisory, VDB Entry
af854a3a-2127-422b-91ae-364da2661108https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333Mailing List, Patch, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6Mailing List, Patch, Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://ubuntu.com/security/notices/USN-4917-1Vendor Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.openwall.com/lists/oss-security/2021/04/16/2Mailing List, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://www.zerodayinitiative.com/advisories/ZDI-21-422/Third Party Advisory, VDB Entry
Impacted products
Vendor Product Version
canonical ubuntu_linux *
canonical ubuntu_linux *
canonical ubuntu_linux *
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "Linux kernel",
          "vendor": "Ubuntu",
          "versions": [
            {
              "lessThan": "5.8.0-50.56",
              "status": "affected",
              "version": "5.8 kernel",
              "versionType": "custom"
            },
            {
              "lessThan": "5.4.0-72.80",
              "status": "affected",
              "version": "5.4 kernel",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "security@ubuntu.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:*",
              "matchCriteriaId": "90A80DE7-3EFA-464C-9D31-C46521FFBFBF",
              "versionEndExcluding": "18.04",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:*",
              "matchCriteriaId": "2027773B-26DA-408E-B71D-40D05690D9EA",
              "versionEndExcluding": "20.04",
              "versionStartIncluding": "18.04.1",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "cpeMatch": [
            {
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              "matchCriteriaId": "ACAB2EE0-EC21-4669-840F-94F6C3028C64",
              "versionEndExcluding": "20.10",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Shiftfs, an out-of-tree stacking file system included in Ubuntu Linux kernels, did not properly handle faults occurring during copy_from_user() correctly. These could lead to either a double-free situation or memory not being freed at all. An attacker could use this to cause a denial of service (kernel memory exhaustion) or gain privileges via executing arbitrary code. AKA ZDI-CAN-13562."
    },
    {
      "lang": "es",
      "value": "Shiftfs, un sistema de archivos de apilamiento fuera del \u00e1rbol incluido en los kernels de Ubuntu Linux, no manejaba apropiadamente los fallos que ocurr\u00edan durante la funci\u00f3n copy_from_user().\u0026#xa0;Esto podr\u00eda conllevar a una situaci\u00f3n de doble liberaci\u00f3n o a que la memoria no sea liberada del todo.\u0026#xa0;Un atacante podr\u00eda usar esto para causar una denegaci\u00f3n de servicio (agotamiento de la memoria del kernel) u alcanzar privilegios por medio de la ejecuci\u00f3n de c\u00f3digo arbitrario.\u0026#xa0;Tambi\u00e9n se conoce como ZDI-CAN-13562"
    }
  ],
  "id": "CVE-2021-3492",
  "lastModified": "2026-06-17T04:05:12.033",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "HIGH",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "LOCAL",
          "authentication": "NONE",
          "availabilityImpact": "COMPLETE",
          "baseScore": 7.2,
          "confidentialityImpact": "COMPLETE",
          "integrityImpact": "COMPLETE",
          "vectorString": "AV:L/AC:L/Au:N/C:C/I:C/A:C",
          "version": "2.0"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 10.0,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.0,
        "impactScore": 6.0,
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        "type": "Secondary"
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          "attackComplexity": "LOW",
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          "confidentialityImpact": "HIGH",
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          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
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        "impactScore": 5.9,
        "source": "nvd@nist.gov",
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  },
  "published": "2021-04-17T05:15:13.113",
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  "sourceIdentifier": "security@ubuntu.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
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          "value": "CWE-401"
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      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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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

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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.
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  • 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.


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