FKIE_CVE-2019-15793

Vulnerability from fkie_nvd - Published: 2020-04-24 00:15 - Updated: 2026-06-17 02:21
Severity
6.5 (Medium) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
8.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Summary
In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, several locations which shift ids translate user/group ids before performing operations in the lower filesystem were translating them into init_user_ns, whereas they should have been translated into the s_user_ns for the lower filesystem. This resulted in using ids other than the intended ones in the lower fs, which likely did not map into the shifts s_user_ns. A local attacker could use this to possibly bypass discretionary access control permissions.
References
security@ubuntu.comhttps://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=3644b9d5688da86f18e017c9c580b75cf52927bbMailing List, Patch, Third Party Advisory
security@ubuntu.comhttps://usn.ubuntu.com/usn/usn-4183-1Third Party Advisory
security@ubuntu.comhttps://usn.ubuntu.com/usn/usn-4184-1Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=3644b9d5688da86f18e017c9c580b75cf52927bbMailing List, Patch, Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://usn.ubuntu.com/usn/usn-4183-1Third Party Advisory
af854a3a-2127-422b-91ae-364da2661108https://usn.ubuntu.com/usn/usn-4184-1Third Party Advisory
Impacted products
Vendor Product Version
linux linux_kernel 5.0
linux linux_kernel 5.3
canonical ubuntu_linux 18.04
canonical ubuntu_linux 19.04
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "Shiftfs in the Linux kernel",
          "vendor": "Ubuntu",
          "versions": [
            {
              "changes": [
                {
                  "at": "5.3.0-22.24",
                  "status": "unaffected"
                }
              ],
              "lessThan": "5.3 kernel*",
              "status": "affected",
              "version": "5.3.0-11.12",
              "versionType": "custom"
            },
            {
              "lessThan": "5.0.0-35.38",
              "status": "affected",
              "version": "5.0 kernel",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "security@ubuntu.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.0:*:*:*:*:*:*:*",
              "matchCriteriaId": "D4300F13-DCE3-40B5-9310-313405468D2F",
              "vulnerable": true
            },
            {
              "criteria": "cpe:2.3:o:linux:linux_kernel:5.3:*:*:*:*:*:*:*",
              "matchCriteriaId": "CF8AA5A5-E882-4063-B2BB-C2268685060E",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    },
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:o:canonical:ubuntu_linux:18.04:*:*:*:lts:*:*:*",
              "matchCriteriaId": "23A7C53F-B80F-4E6A-AFA9-58EEA84BE11D",
              "vulnerable": true
            },
            {
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              "matchCriteriaId": "CD783B0C-9246-47D9-A937-6144FE8BFF0F",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In shiftfs, a non-upstream patch to the Linux kernel included in the Ubuntu 5.0 and 5.3 kernel series, several locations which shift ids translate user/group ids before performing operations in the lower filesystem were translating them into init_user_ns, whereas they should have been translated into the s_user_ns for the lower filesystem. This resulted in using ids other than the intended ones in the lower fs, which likely did not map into the shifts s_user_ns. A local attacker could use this to possibly bypass discretionary access control permissions."
    },
    {
      "lang": "es",
      "value": "En shiftfs, un parche no upstream para el Kernel de Linux  incluido en las series kernel de Ubuntu versiones 5.0 y 5.3, varias ubicaciones que desplazan los ids traducen los ids de usuario/grupo antes de realizar operaciones en el sistema de archivos inferior los estaban traduciendo a init_user_ns, mientras que deber\u00edan haber sido traducidos a s_user_ns para el sistema de archivos inferior. Esto dio lugar a que se utilizaran ids distintos de los previstos en los fs inferiores, que probablemente no se mapearon en los shifts s_user_ns. Un atacante local podr\u00eda usar esto para posiblemente eludir los permisos de control de acceso discrecional."
    }
  ],
  "id": "CVE-2019-15793",
  "lastModified": "2026-06-17T02:21:05.183",
  "metrics": {
    "cvssMetricV2": [
      {
        "acInsufInfo": false,
        "baseSeverity": "MEDIUM",
        "cvssData": {
          "accessComplexity": "LOW",
          "accessVector": "LOCAL",
          "authentication": "NONE",
          "availabilityImpact": "PARTIAL",
          "baseScore": 4.6,
          "confidentialityImpact": "PARTIAL",
          "integrityImpact": "PARTIAL",
          "vectorString": "AV:L/AC:L/Au:N/C:P/I:P/A:P",
          "version": "2.0"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 6.4,
        "obtainAllPrivilege": false,
        "obtainOtherPrivilege": false,
        "obtainUserPrivilege": false,
        "source": "nvd@nist.gov",
        "type": "Primary",
        "userInteractionRequired": false
      }
    ],
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "NONE",
          "baseScore": 6.5,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 2.0,
        "impactScore": 4.0,
        "source": "security@ubuntu.com",
        "type": "Secondary"
      },
      {
        "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,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ]
  },
  "published": "2020-04-24T00:15:11.840",
  "references": [
    {
      "source": "security@ubuntu.com",
      "tags": [
        "Mailing List",
        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=3644b9d5688da86f18e017c9c580b75cf52927bb"
    },
    {
      "source": "security@ubuntu.com",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://usn.ubuntu.com/usn/usn-4183-1"
    },
    {
      "source": "security@ubuntu.com",
      "tags": [
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      ],
      "url": "https://usn.ubuntu.com/usn/usn-4184-1"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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        "Patch",
        "Third Party Advisory"
      ],
      "url": "https://git.launchpad.net/~ubuntu-kernel/ubuntu/+source/linux/+git/eoan/commit/?id=3644b9d5688da86f18e017c9c580b75cf52927bb"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
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      "url": "https://usn.ubuntu.com/usn/usn-4183-1"
    },
    {
      "source": "af854a3a-2127-422b-91ae-364da2661108",
      "tags": [
        "Third Party Advisory"
      ],
      "url": "https://usn.ubuntu.com/usn/usn-4184-1"
    }
  ],
  "sourceIdentifier": "security@ubuntu.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-538"
        }
      ],
      "source": "security@ubuntu.com",
      "type": "Secondary"
    },
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-276"
        }
      ],
      "source": "nvd@nist.gov",
      "type": "Primary"
    }
  ]
}



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