CVE-2021-3492 (GCVE-0-2021-3492)

Vulnerability from cvelistv5 – Published: 2021-04-17 04:20 – Updated: 2024-09-17 03:54
VLAI
Title
Ubuntu linux kernel shiftfs file system double free vulnerability
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.
Severity
8.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
CWE
  • CWE-415 - Double Free
  • CWE-401 - Missing Release of Memory after Effective Lifetime
Assigner
References
Impacted products
Vendor Product Version
Ubuntu Linux kernel Affected: 5.8 kernel , < 5.8.0-50.56 (custom)
Affected: 5.4 kernel , < 5.4.0-72.80 (custom)
Create a notification for this product.
Date Public
2021-04-15 00:00
Credits
Vincent Dehors of Synactiv Digital Security
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-03T16:53:17.692Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://www.openwall.com/lists/oss-security/2021/04/16/2"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://ubuntu.com/security/notices/USN-4917-1"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-422/"
          },
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "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"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Vincent Dehors of Synactiv Digital Security"
        }
      ],
      "datePublic": "2021-04-15T00:00:00.000Z",
      "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "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"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-415",
              "description": "CWE-415: Double Free",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-401",
              "description": "CWE-401: Missing Release of Memory after Effective Lifetime",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2021-05-18T17:06:14.000Z",
        "orgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc",
        "shortName": "canonical"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://www.openwall.com/lists/oss-security/2021/04/16/2"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://ubuntu.com/security/notices/USN-4917-1"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-422/"
        },
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.html"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "Ubuntu linux kernel shiftfs file system double free vulnerability",
      "x_generator": {
        "engine": "Vulnogram 0.0.9"
      },
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "security@ubuntu.com",
          "DATE_PUBLIC": "2021-04-15T00:00:00.000Z",
          "ID": "CVE-2021-3492",
          "STATE": "PUBLIC",
          "TITLE": "Ubuntu linux kernel shiftfs file system double free vulnerability"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "Linux kernel",
                      "version": {
                        "version_data": [
                          {
                            "version_affected": "\u003c",
                            "version_name": "5.8 kernel",
                            "version_value": "5.8.0-50.56"
                          },
                          {
                            "version_affected": "\u003c",
                            "version_name": "5.4 kernel",
                            "version_value": "5.4.0-72.80"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "Ubuntu"
              }
            ]
          }
        },
        "credit": [
          {
            "lang": "eng",
            "value": "Vincent Dehors of Synactiv Digital Security"
          }
        ],
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "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."
            }
          ]
        },
        "generator": {
          "engine": "Vulnogram 0.0.9"
        },
        "impact": {
          "cvss": {
            "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"
          }
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-415: Double Free"
                }
              ]
            },
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-401: Missing Release of Memory after Effective Lifetime"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://www.openwall.com/lists/oss-security/2021/04/16/2",
              "refsource": "MISC",
              "url": "https://www.openwall.com/lists/oss-security/2021/04/16/2"
            },
            {
              "name": "https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6",
              "refsource": "MISC",
              "url": "https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6"
            },
            {
              "name": "https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333",
              "refsource": "MISC",
              "url": "https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333"
            },
            {
              "name": "https://ubuntu.com/security/notices/USN-4917-1",
              "refsource": "MISC",
              "url": "https://ubuntu.com/security/notices/USN-4917-1"
            },
            {
              "name": "https://www.zerodayinitiative.com/advisories/ZDI-21-422/",
              "refsource": "MISC",
              "url": "https://www.zerodayinitiative.com/advisories/ZDI-21-422/"
            },
            {
              "name": "http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.html",
              "refsource": "MISC",
              "url": "http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.html"
            }
          ]
        },
        "source": {
          "discovery": "EXTERNAL"
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc",
    "assignerShortName": "canonical",
    "cveId": "CVE-2021-3492",
    "datePublished": "2021-04-17T04:20:16.011Z",
    "dateReserved": "2021-04-09T00:00:00.000Z",
    "dateUpdated": "2024-09-17T03:54:52.527Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2021-3492",
      "date": "2026-07-21",
      "epss": "0.01547",
      "percentile": "0.72307"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2021-3492\",\"sourceIdentifier\":\"security@ubuntu.com\",\"published\":\"2021-04-17T05:15:13.113\",\"lastModified\":\"2024-11-21T06:21:40.257\",\"vulnStatus\":\"Modified\",\"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\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security@ubuntu.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H\",\"baseScore\":8.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.0,\"impactScore\":6.0},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":7.8,\"baseSeverity\":\"HIGH\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"LOW\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":1.8,\"impactScore\":5.9}],\"cvssMetricV2\":[{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"cvssData\":{\"version\":\"2.0\",\"vectorString\":\"AV:L/AC:L/Au:N/C:C/I:C/A:C\",\"baseScore\":7.2,\"accessVector\":\"LOCAL\",\"accessComplexity\":\"LOW\",\"authentication\":\"NONE\",\"confidentialityImpact\":\"COMPLETE\",\"integrityImpact\":\"COMPLETE\",\"availabilityImpact\":\"COMPLETE\"},\"baseSeverity\":\"HIGH\",\"exploitabilityScore\":3.9,\"impactScore\":10.0,\"acInsufInfo\":false,\"obtainAllPrivilege\":false,\"obtainUserPrivilege\":false,\"obtainOtherPrivilege\":false,\"userInteractionRequired\":false}]},\"weaknesses\":[{\"source\":\"security@ubuntu.com\",\"type\":\"Secondary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-401\"},{\"lang\":\"en\",\"value\":\"CWE-415\"}]},{\"source\":\"nvd@nist.gov\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-401\"},{\"lang\":\"en\",\"value\":\"CWE-415\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:*\",\"versionEndExcluding\":\"18.04\",\"matchCriteriaId\":\"90A80DE7-3EFA-464C-9D31-C46521FFBFBF\"},{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:lts:*:*:*\",\"versionStartIncluding\":\"18.04.1\",\"versionEndExcluding\":\"20.04\",\"matchCriteriaId\":\"2027773B-26DA-408E-B71D-40D05690D9EA\"}]}]},{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:o:canonical:ubuntu_linux:*:*:*:*:-:*:*:*\",\"versionEndExcluding\":\"20.10\",\"matchCriteriaId\":\"ACAB2EE0-EC21-4669-840F-94F6C3028C64\"}]}]}],\"references\":[{\"url\":\"http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.html\",\"source\":\"security@ubuntu.com\",\"tags\":[\"Third Party Advisory\",\"VDB Entry\"]},{\"url\":\"https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333\",\"source\":\"security@ubuntu.com\",\"tags\":[\"Mailing List\",\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6\",\"source\":\"security@ubuntu.com\",\"tags\":[\"Mailing List\",\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://ubuntu.com/security/notices/USN-4917-1\",\"source\":\"security@ubuntu.com\",\"tags\":[\"Vendor Advisory\"]},{\"url\":\"https://www.openwall.com/lists/oss-security/2021/04/16/2\",\"source\":\"security@ubuntu.com\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"https://www.zerodayinitiative.com/advisories/ZDI-21-422/\",\"source\":\"security@ubuntu.com\",\"tags\":[\"Third Party Advisory\",\"VDB Entry\"]},{\"url\":\"http://packetstormsecurity.com/files/162614/Kernel-Live-Patch-Security-Notice-LSN-0077-1.html\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\",\"VDB Entry\"]},{\"url\":\"https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=25c891a949bf918b59cbc6e4932015ba4c35c333\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/focal/commit/?id=8fee52ab9da87d82bc6de9ebb3480fff9b4d53e6\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Patch\",\"Vendor Advisory\"]},{\"url\":\"https://ubuntu.com/security/notices/USN-4917-1\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Vendor Advisory\"]},{\"url\":\"https://www.openwall.com/lists/oss-security/2021/04/16/2\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Mailing List\",\"Third Party Advisory\"]},{\"url\":\"https://www.zerodayinitiative.com/advisories/ZDI-21-422/\",\"source\":\"af854a3a-2127-422b-91ae-364da2661108\",\"tags\":[\"Third Party Advisory\",\"VDB Entry\"]}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-28T06:25:40+00:00",
      "cve": "CVE-2021-3492",
      "id": "CVE-2021-3492",
      "initial_release_date": "2021-04-16T00:00:00+00:00",
      "product_status:known_not_affected": "197",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: shiftfs file system double free vulnerability",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2021/cve-2021-3492.json",
      "version": "3"
    }
  }
}



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.