CVE-2020-8833 (GCVE-0-2020-8833)

Vulnerability from cvelistv5 – Published: 2020-04-22 21:15 – Updated: 2024-09-16 20:53
VLAI
Title
Apport race condition in crash report permissions
Summary
Time-of-check Time-of-use Race Condition vulnerability on crash report ownership change in Apport allows for a possible privilege escalation opportunity. If fs.protected_symlinks is disabled, this can be exploited between the os.open and os.chown calls when the Apport cron script clears out crash files of size 0. A symlink with the same name as the deleted file can then be created upon which chown will be called, changing the file owner to root. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22.
Severity
5.6 (Medium)
CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N
CWE
  • CWE-367 - Time-of-check Time-of-use (TOCTOU) Race Condition
Assigner
References
URL Tags
https://usn.ubuntu.com/4315-1/ x_refsource_CONFIRM
https://bugs.launchpad.net/ubuntu/+source/apport/… x_refsource_CONFIRM
https://usn.ubuntu.com/4315-2/ vendor-advisoryx_refsource_UBUNTU
Impacted products
Vendor Product Version CPE status
Canonical Apport Affected: 2.20.1 , < 2.20.1-0ubuntu2.23 (custom)
Affected: 2.20.9 , < 2.20.9-0ubuntu7.14 (custom)
Affected: 2.20.11 , < 2.20.11-0ubuntu8.8 (custom)
guessed Create a notification for this product.
Date Public
2020-04-02 00:00
Credits
Maximilien Bourgeteau
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T10:12:10.622Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://usn.ubuntu.com/4315-1/"
          },
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933"
          },
          {
            "name": "USN-4315-2",
            "tags": [
              "vendor-advisory",
              "x_refsource_UBUNTU",
              "x_transferred"
            ],
            "url": "https://usn.ubuntu.com/4315-2/"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "Apport",
          "vendor": "Canonical",
          "versions": [
            {
              "lessThan": "2.20.1-0ubuntu2.23",
              "status": "affected",
              "version": "2.20.1",
              "versionType": "custom"
            },
            {
              "lessThan": "2.20.9-0ubuntu7.14",
              "status": "affected",
              "version": "2.20.9",
              "versionType": "custom"
            },
            {
              "changes": [
                {
                  "at": "2.20.11-0ubuntu22",
                  "status": "unaffected"
                }
              ],
              "lessThan": "2.20.11-0ubuntu8.8",
              "status": "affected",
              "version": "2.20.11",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "value": "Maximilien Bourgeteau"
        }
      ],
      "datePublic": "2020-04-02T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Time-of-check Time-of-use Race Condition vulnerability on crash report ownership change in Apport allows for a possible privilege escalation opportunity. If fs.protected_symlinks is disabled, this can be exploited between the os.open and os.chown calls when the Apport cron script clears out crash files of size 0. A symlink with the same name as the deleted file can then be created upon which chown will be called, changing the file owner to root. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 5.6,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-367",
              "description": "CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2020-06-24T20:06:03.000Z",
        "orgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc",
        "shortName": "canonical"
      },
      "references": [
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://usn.ubuntu.com/4315-1/"
        },
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933"
        },
        {
          "name": "USN-4315-2",
          "tags": [
            "vendor-advisory",
            "x_refsource_UBUNTU"
          ],
          "url": "https://usn.ubuntu.com/4315-2/"
        }
      ],
      "source": {
        "advisory": "https://usn.ubuntu.com/4315-1/",
        "defect": [
          "https://launchpad.net/bugs/1862933"
        ],
        "discovery": "EXTERNAL"
      },
      "title": "Apport race condition in crash report permissions",
      "x_generator": {
        "engine": "Vulnogram 0.0.9"
      },
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "AKA": "",
          "ASSIGNER": "security@ubuntu.com",
          "DATE_PUBLIC": "2020-04-02T00:43:00.000Z",
          "ID": "CVE-2020-8833",
          "STATE": "PUBLIC",
          "TITLE": "Apport race condition in crash report permissions"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "Apport",
                      "version": {
                        "version_data": [
                          {
                            "platform": "",
                            "version_affected": "\u003c",
                            "version_name": "2.20.1",
                            "version_value": "2.20.1-0ubuntu2.23"
                          },
                          {
                            "platform": "",
                            "version_affected": "\u003c",
                            "version_name": "2.20.9",
                            "version_value": "2.20.9-0ubuntu7.14"
                          },
                          {
                            "platform": "",
                            "version_affected": "\u003c",
                            "version_name": "2.20.11",
                            "version_value": "2.20.11-0ubuntu8.8"
                          },
                          {
                            "platform": "",
                            "version_affected": "\u003c",
                            "version_name": "2.20.11",
                            "version_value": "2.20.11-0ubuntu22"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "Canonical"
              }
            ]
          }
        },
        "configuration": [],
        "credit": [
          {
            "lang": "eng",
            "value": "Maximilien Bourgeteau"
          }
        ],
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "Time-of-check Time-of-use Race Condition vulnerability on crash report ownership change in Apport allows for a possible privilege escalation opportunity. If fs.protected_symlinks is disabled, this can be exploited between the os.open and os.chown calls when the Apport cron script clears out crash files of size 0. A symlink with the same name as the deleted file can then be created upon which chown will be called, changing the file owner to root. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22."
            }
          ]
        },
        "exploit": [],
        "generator": {
          "engine": "Vulnogram 0.0.9"
        },
        "impact": {
          "cvss": {
            "attackComplexity": "HIGH",
            "attackVector": "LOCAL",
            "availabilityImpact": "NONE",
            "baseScore": 5.6,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N",
            "version": "3.1"
          }
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-367 Time-of-check Time-of-use (TOCTOU) Race Condition"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://usn.ubuntu.com/4315-1/",
              "refsource": "CONFIRM",
              "url": "https://usn.ubuntu.com/4315-1/"
            },
            {
              "name": "https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933",
              "refsource": "CONFIRM",
              "url": "https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933"
            },
            {
              "name": "USN-4315-2",
              "refsource": "UBUNTU",
              "url": "https://usn.ubuntu.com/4315-2/"
            }
          ]
        },
        "solution": [],
        "source": {
          "advisory": "https://usn.ubuntu.com/4315-1/",
          "defect": [
            "https://launchpad.net/bugs/1862933"
          ],
          "discovery": "EXTERNAL"
        },
        "work_around": []
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "cc1ad9ee-3454-478d-9317-d3e869d708bc",
    "assignerShortName": "canonical",
    "cveId": "CVE-2020-8833",
    "datePublished": "2020-04-22T21:15:18.859Z",
    "dateReserved": "2020-02-10T00:00:00.000Z",
    "dateUpdated": "2024-09-16T20:53:27.660Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2020-8833",
      "date": "2026-09-22",
      "epss": "0.00344",
      "percentile": "0.2799"
    },
    "nvd": {
      "cve": {
        "configurations": [
          {
            "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
                  },
                  {
                    "criteria": "cpe:2.3:o:canonical:ubuntu_linux:19.10:*:*:*:*:*:*:*",
                    "matchCriteriaId": "A31C8344-3E02-4EB8-8BD8-4C84B7959624",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:apport_project:apport:-:*:*:*:*:*:*:*",
                    "matchCriteriaId": "47363193-B4DB-4654-BFAC-373426212337",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Time-of-check Time-of-use Race Condition vulnerability on crash report ownership change in Apport allows for a possible privilege escalation opportunity. If fs.protected_symlinks is disabled, this can be exploited between the os.open and os.chown calls when the Apport cron script clears out crash files of size 0. A symlink with the same name as the deleted file can then be created upon which chown will be called, changing the file owner to root. Fixed in versions 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 and 2.20.11-0ubuntu22."
          },
          {
            "lang": "es",
            "value": "Una vulnerabilidad de Condici\u00f3n de Carrera de tipo Time-of-check Time-of-use en el cambio de propiedad del reporte de bloqueo en Apport, permite una posible oportunidad de escalada de privilegios. Si fs.protected_symlinks est\u00e1 deshabilitado, esto puede ser explotado entre las llamadas de os.open y os.chown cuando el script cron de Apport borra los archivos bloqueados de tama\u00f1o 0. Un enlace simb\u00f3lico con el mismo nombre que el archivo eliminado puede entonces ser creado a partir de que chown ser\u00eda llamado, cambiando el propietario del archivo a root. Corregido en las versiones 2.20.1-0ubuntu2.23, 2.20.9-0ubuntu7.14, 2.20.11-0ubuntu8.8 y 2.20.11-0ubuntu22."
          }
        ],
        "id": "CVE-2020-8833",
        "lastModified": "2024-11-21T05:39:31.937",
        "metrics": {
          "cvssMetricV2": [
            {
              "acInsufInfo": false,
              "baseSeverity": "LOW",
              "cvssData": {
                "accessComplexity": "MEDIUM",
                "accessVector": "LOCAL",
                "authentication": "NONE",
                "availabilityImpact": "NONE",
                "baseScore": 1.9,
                "confidentialityImpact": "PARTIAL",
                "integrityImpact": "NONE",
                "vectorString": "AV:L/AC:M/Au:N/C:P/I:N/A:N",
                "version": "2.0"
              },
              "exploitabilityScore": 3.4,
              "impactScore": 2.9,
              "obtainAllPrivilege": false,
              "obtainOtherPrivilege": false,
              "obtainUserPrivilege": false,
              "source": "nvd@nist.gov",
              "type": "Primary",
              "userInteractionRequired": false
            }
          ],
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "LOCAL",
                "availabilityImpact": "NONE",
                "baseScore": 5.6,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "NONE",
                "privilegesRequired": "LOW",
                "scope": "CHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 1.1,
              "impactScore": 4.0,
              "source": "security@ubuntu.com",
              "type": "Secondary"
            },
            {
              "cvssData": {
                "attackComplexity": "HIGH",
                "attackVector": "LOCAL",
                "availabilityImpact": "NONE",
                "baseScore": 4.7,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "NONE",
                "privilegesRequired": "LOW",
                "scope": "UNCHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 1.0,
              "impactScore": 3.6,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ]
        },
        "published": "2020-04-22T22:15:12.577",
        "references": [
          {
            "source": "security@ubuntu.com",
            "tags": [
              "Exploit",
              "Third Party Advisory"
            ],
            "url": "https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933"
          },
          {
            "source": "security@ubuntu.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/4315-1/"
          },
          {
            "source": "security@ubuntu.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/4315-2/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Exploit",
              "Third Party Advisory"
            ],
            "url": "https://bugs.launchpad.net/ubuntu/+source/apport/+bug/1862933"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/4315-1/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://usn.ubuntu.com/4315-2/"
          }
        ],
        "sourceIdentifier": "security@ubuntu.com",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-367"
              }
            ],
            "source": "security@ubuntu.com",
            "type": "Secondary"
          },
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-367"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "current_release_date": "2026-02-24T01:34:43+00:00",
      "cve": "CVE-2020-8833",
      "id": "CVE-2020-8833",
      "initial_release_date": "2020-04-02T00:00:00+00:00",
      "product_status:known_not_affected": "1",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "Apport race condition in crash report permissions",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2020/cve-2020-8833.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.


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.