GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2020-27821 (GCVE-0-2020-27821)

Vulnerability from cvelistv5 – Published: 2020-12-08 21:33 – Updated: 2024-08-04 16:25
VLAI
Summary
A flaw was found in the memory management API of QEMU during the initialization of a memory region cache. This issue could lead to an out-of-bounds write access to the MSI-X table while performing MMIO operations. A guest user may abuse this flaw to crash the QEMU process on the host, resulting in a denial of service. This flaw affects QEMU versions prior to 5.2.0.
CWE
Impacted products
Vendor Product Version CPE status
n/a QEMU Affected: prior to 5.2.0
Show details on NVD website

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-04T16:25:42.445Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1902651"
          },
          {
            "name": "[oss-security] 20201216 CVE-2020-27821 QEMU: heap buffer overflow in msix_table_mmio_write() in hw/pci/msix.c",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "http://www.openwall.com/lists/oss-security/2020/12/16/6"
          },
          {
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20210115-0006/"
          },
          {
            "name": "[debian-lts-announce] 20220905 [SECURITY] [DLA 3099-1] qemu security update",
            "tags": [
              "mailing-list",
              "x_refsource_MLIST",
              "x_transferred"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html"
          }
        ],
        "title": "CVE Program Container"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "QEMU",
          "vendor": "n/a",
          "versions": [
            {
              "status": "affected",
              "version": "prior to 5.2.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw was found in the memory management API of QEMU during the initialization of a memory region cache. This issue could lead to an out-of-bounds write access to the MSI-X table while performing MMIO operations. A guest user may abuse this flaw to crash the QEMU process on the host, resulting in a denial of service. This flaw affects QEMU versions prior to 5.2.0."
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-787",
              "description": "CWE-787-\u003eCWE-122",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2022-09-05T05:06:30.000Z",
        "orgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
        "shortName": "redhat"
      },
      "references": [
        {
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1902651"
        },
        {
          "name": "[oss-security] 20201216 CVE-2020-27821 QEMU: heap buffer overflow in msix_table_mmio_write() in hw/pci/msix.c",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "http://www.openwall.com/lists/oss-security/2020/12/16/6"
        },
        {
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://security.netapp.com/advisory/ntap-20210115-0006/"
        },
        {
          "name": "[debian-lts-announce] 20220905 [SECURITY] [DLA 3099-1] qemu security update",
          "tags": [
            "mailing-list",
            "x_refsource_MLIST"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html"
        }
      ],
      "x_legacyV4Record": {
        "CVE_data_meta": {
          "ASSIGNER": "secalert@redhat.com",
          "ID": "CVE-2020-27821",
          "STATE": "PUBLIC"
        },
        "affects": {
          "vendor": {
            "vendor_data": [
              {
                "product": {
                  "product_data": [
                    {
                      "product_name": "QEMU",
                      "version": {
                        "version_data": [
                          {
                            "version_value": "prior to 5.2.0"
                          }
                        ]
                      }
                    }
                  ]
                },
                "vendor_name": "n/a"
              }
            ]
          }
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "eng",
              "value": "A flaw was found in the memory management API of QEMU during the initialization of a memory region cache. This issue could lead to an out-of-bounds write access to the MSI-X table while performing MMIO operations. A guest user may abuse this flaw to crash the QEMU process on the host, resulting in a denial of service. This flaw affects QEMU versions prior to 5.2.0."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "eng",
                  "value": "CWE-787-\u003eCWE-122"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://bugzilla.redhat.com/show_bug.cgi?id=1902651",
              "refsource": "MISC",
              "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1902651"
            },
            {
              "name": "[oss-security] 20201216 CVE-2020-27821 QEMU: heap buffer overflow in msix_table_mmio_write() in hw/pci/msix.c",
              "refsource": "MLIST",
              "url": "http://www.openwall.com/lists/oss-security/2020/12/16/6"
            },
            {
              "name": "https://security.netapp.com/advisory/ntap-20210115-0006/",
              "refsource": "CONFIRM",
              "url": "https://security.netapp.com/advisory/ntap-20210115-0006/"
            },
            {
              "name": "[debian-lts-announce] 20220905 [SECURITY] [DLA 3099-1] qemu security update",
              "refsource": "MLIST",
              "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html"
            }
          ]
        }
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "53f830b8-0a3f-465b-8143-3b8a9948e749",
    "assignerShortName": "redhat",
    "cveId": "CVE-2020-27821",
    "datePublished": "2020-12-08T21:33:02.000Z",
    "dateReserved": "2020-10-27T00:00:00.000Z",
    "dateUpdated": "2024-08-04T16:25:42.445Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2020-27821",
      "date": "2026-09-17",
      "epss": "0.00364",
      "percentile": "0.30109"
    },
    "fkie_nvd": {
      "configurations": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*",
                  "matchCriteriaId": "6BB4748D-7B13-45A4-92E3-8AB072BB0FE6",
                  "versionEndExcluding": "5.2.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        },
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
                  "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "A flaw was found in the memory management API of QEMU during the initialization of a memory region cache. This issue could lead to an out-of-bounds write access to the MSI-X table while performing MMIO operations. A guest user may abuse this flaw to crash the QEMU process on the host, resulting in a denial of service. This flaw affects QEMU versions prior to 5.2.0."
        },
        {
          "lang": "es",
          "value": "Se encontr\u00f3 uno fallo en la API de administraci\u00f3n de memoria de QEMU durante la inicializaci\u00f3n de una cach\u00e9 de regi\u00f3n de memoria.\u0026#xa0;Este problema podr\u00eda conllevar un acceso de escritura fuera de los l\u00edmites a la tabla MSI-X mientras se llevan a cabo operaciones MMIO.\u0026#xa0;Un usuario invitado puede abusar de este fallo para bloquear el proceso QEMU en el host, resultando en una denegaci\u00f3n de servicio.\u0026#xa0;Este fallo afecta a QEMU versiones anteriores a 5.2.0"
        }
      ],
      "id": "CVE-2020-27821",
      "lastModified": "2024-11-21T05:21:52.553",
      "metrics": {
        "cvssMetricV2": [
          {
            "acInsufInfo": false,
            "baseSeverity": "LOW",
            "cvssData": {
              "accessComplexity": "LOW",
              "accessVector": "LOCAL",
              "authentication": "NONE",
              "availabilityImpact": "PARTIAL",
              "baseScore": 2.1,
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "vectorString": "AV:L/AC:L/Au:N/C:N/I:N/A:P",
              "version": "2.0"
            },
            "exploitabilityScore": 3.9,
            "impactScore": 2.9,
            "obtainAllPrivilege": false,
            "obtainOtherPrivilege": false,
            "obtainUserPrivilege": false,
            "source": "nvd@nist.gov",
            "type": "Primary",
            "userInteractionRequired": false
          }
        ],
        "cvssMetricV31": [
          {
            "cvssData": {
              "attackComplexity": "LOW",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 6.0,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "HIGH",
              "scope": "CHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H",
              "version": "3.1"
            },
            "exploitabilityScore": 1.5,
            "impactScore": 4.0,
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      },
      "published": "2020-12-08T22:15:18.587",
      "references": [
        {
          "source": "secalert@redhat.com",
          "tags": [
            "Mailing List",
            "Third Party Advisory"
          ],
          "url": "http://www.openwall.com/lists/oss-security/2020/12/16/6"
        },
        {
          "source": "secalert@redhat.com",
          "tags": [
            "Issue Tracking",
            "Patch",
            "Third Party Advisory"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1902651"
        },
        {
          "source": "secalert@redhat.com",
          "tags": [
            "Mailing List",
            "Third Party Advisory"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html"
        },
        {
          "source": "secalert@redhat.com",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://security.netapp.com/advisory/ntap-20210115-0006/"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Mailing List",
            "Third Party Advisory"
          ],
          "url": "http://www.openwall.com/lists/oss-security/2020/12/16/6"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Issue Tracking",
            "Patch",
            "Third Party Advisory"
          ],
          "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1902651"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Mailing List",
            "Third Party Advisory"
          ],
          "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html"
        },
        {
          "source": "af854a3a-2127-422b-91ae-364da2661108",
          "tags": [
            "Third Party Advisory"
          ],
          "url": "https://security.netapp.com/advisory/ntap-20210115-0006/"
        }
      ],
      "sourceIdentifier": "secalert@redhat.com",
      "vulnStatus": "Modified",
      "weaknesses": [
        {
          "description": [
            {
              "lang": "en",
              "value": "CWE-787"
            }
          ],
          "source": "secalert@redhat.com",
          "type": "Secondary"
        },
        {
          "description": [
            {
              "lang": "en",
              "value": "CWE-787"
            }
          ],
          "source": "nvd@nist.gov",
          "type": "Primary"
        }
      ]
    },
    "microsoft_vex": {
      "current_release_date": "2020-12-11T00:00:00.000Z",
      "cve": "CVE-2020-27821",
      "id": "msrc_CVE-2020-27821",
      "initial_release_date": "2020-12-02T00:00:00.000Z",
      "product_status:fixed": "1",
      "product_status:known_affected": "1",
      "source": "Microsoft CSAF VEX",
      "status": "final",
      "title": "A flaw was found in the memory management API of QEMU during the initialization of a memory region cache. This issue could lead to an out-of-bounds write access to the MSI-X table while performing MMIO operations. A guest user may abuse this flaw to crash the QEMU process on the host resulting in a denial of service. This flaw affects QEMU versions prior to 5.2.0.",
      "url": "https://msrc.microsoft.com/csaf/vex/2020/msrc_cve-2020-27821.json",
      "version": "1"
    },
    "nvd": {
      "cve": {
        "configurations": [
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:a:qemu:qemu:*:*:*:*:*:*:*:*",
                    "matchCriteriaId": "6BB4748D-7B13-45A4-92E3-8AB072BB0FE6",
                    "versionEndExcluding": "5.2.0",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          },
          {
            "nodes": [
              {
                "cpeMatch": [
                  {
                    "criteria": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
                    "matchCriteriaId": "07B237A9-69A3-4A9C-9DA0-4E06BD37AE73",
                    "vulnerable": true
                  }
                ],
                "negate": false,
                "operator": "OR"
              }
            ]
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "A flaw was found in the memory management API of QEMU during the initialization of a memory region cache. This issue could lead to an out-of-bounds write access to the MSI-X table while performing MMIO operations. A guest user may abuse this flaw to crash the QEMU process on the host, resulting in a denial of service. This flaw affects QEMU versions prior to 5.2.0."
          },
          {
            "lang": "es",
            "value": "Se encontr\u00f3 uno fallo en la API de administraci\u00f3n de memoria de QEMU durante la inicializaci\u00f3n de una cach\u00e9 de regi\u00f3n de memoria.\u0026#xa0;Este problema podr\u00eda conllevar un acceso de escritura fuera de los l\u00edmites a la tabla MSI-X mientras se llevan a cabo operaciones MMIO.\u0026#xa0;Un usuario invitado puede abusar de este fallo para bloquear el proceso QEMU en el host, resultando en una denegaci\u00f3n de servicio.\u0026#xa0;Este fallo afecta a QEMU versiones anteriores a 5.2.0"
          }
        ],
        "id": "CVE-2020-27821",
        "lastModified": "2024-11-21T05:21:52.553",
        "metrics": {
          "cvssMetricV2": [
            {
              "acInsufInfo": false,
              "baseSeverity": "LOW",
              "cvssData": {
                "accessComplexity": "LOW",
                "accessVector": "LOCAL",
                "authentication": "NONE",
                "availabilityImpact": "PARTIAL",
                "baseScore": 2.1,
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "vectorString": "AV:L/AC:L/Au:N/C:N/I:N/A:P",
                "version": "2.0"
              },
              "exploitabilityScore": 3.9,
              "impactScore": 2.9,
              "obtainAllPrivilege": false,
              "obtainOtherPrivilege": false,
              "obtainUserPrivilege": false,
              "source": "nvd@nist.gov",
              "type": "Primary",
              "userInteractionRequired": false
            }
          ],
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "LOCAL",
                "availabilityImpact": "HIGH",
                "baseScore": 6.0,
                "baseSeverity": "MEDIUM",
                "confidentialityImpact": "NONE",
                "integrityImpact": "NONE",
                "privilegesRequired": "HIGH",
                "scope": "CHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H",
                "version": "3.1"
              },
              "exploitabilityScore": 1.5,
              "impactScore": 4.0,
              "source": "nvd@nist.gov",
              "type": "Primary"
            }
          ]
        },
        "published": "2020-12-08T22:15:18.587",
        "references": [
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "http://www.openwall.com/lists/oss-security/2020/12/16/6"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Issue Tracking",
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1902651"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html"
          },
          {
            "source": "secalert@redhat.com",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20210115-0006/"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "http://www.openwall.com/lists/oss-security/2020/12/16/6"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Issue Tracking",
              "Patch",
              "Third Party Advisory"
            ],
            "url": "https://bugzilla.redhat.com/show_bug.cgi?id=1902651"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Mailing List",
              "Third Party Advisory"
            ],
            "url": "https://lists.debian.org/debian-lts-announce/2022/09/msg00008.html"
          },
          {
            "source": "af854a3a-2127-422b-91ae-364da2661108",
            "tags": [
              "Third Party Advisory"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20210115-0006/"
          }
        ],
        "sourceIdentifier": "secalert@redhat.com",
        "vulnStatus": "Modified",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-787"
              }
            ],
            "source": "secalert@redhat.com",
            "type": "Secondary"
          },
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-787"
              }
            ],
            "source": "nvd@nist.gov",
            "type": "Primary"
          }
        ]
      }
    },
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-06-28T07:36:59+00:00",
      "cve": "CVE-2020-27821",
      "id": "CVE-2020-27821",
      "initial_release_date": "2020-12-03T00:00:00+00:00",
      "product_status:fixed": "1783",
      "product_status:known_affected": "54",
      "product_status:known_not_affected": "57",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "QEMU: heap buffer overflow in msix_table_mmio_write() in hw/pci/msix.c",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2020/cve-2020-27821.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-05-27T05:46:34Z",
      "cve": "CVE-2020-27821",
      "id": "CVE-2020-27821",
      "initial_release_date": "2023-02-15T03:52:19Z",
      "product_status:known_affected": "368",
      "product_status:known_not_affected": "245",
      "product_status:recommended": "1555",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2020-27821",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2020-27821.json",
      "version": "35"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

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.

Loading…

Detection rules are retrieved from Rulezet.

Loading…

Loading…

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.


Loading…