gsd-2021-28697
Vulnerability from gsd
Modified
2023-12-13 01:23
Details
grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes.
Aliases
Aliases
CVE-2021-28697


To clipboard 

{
  "GSD": {
    "alias": "CVE-2021-28697",
    "description": "grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes.",
    "id": "GSD-2021-28697",
    "references": [
      "https://www.suse.com/security/cve/CVE-2021-28697.html",
      "https://www.debian.org/security/2021/dsa-4977",
      "https://linux.oracle.com/cve/CVE-2021-28697.html"
    ]
  },
  "gsd": {
    "metadata": {
      "exploitCode": "unknown",
      "remediation": "unknown",
      "reportConfidence": "confirmed",
      "type": "vulnerability"
    },
    "osvSchema": {
      "aliases": [
        "CVE-2021-28697"
      ],
      "details": "grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes.",
      "id": "GSD-2021-28697",
      "modified": "2023-12-13T01:23:29.190779Z",
      "schema_version": "1.4.0"
    }
  },
  "namespaces": {
    "cve.org": {
      "CVE_data_meta": {
        "ASSIGNER": "security@xen.org",
        "ID": "CVE-2021-28697",
        "STATE": "PUBLIC"
      },
      "affects": {
        "vendor": {
          "vendor_data": [
            {
              "product": {
                "product_data": [
                  {
                    "product_name": "xen",
                    "version": {
                      "version_data": [
                        {
                          "version_value": "xen-unstable"
                        }
                      ]
                    }
                  },
                  {
                    "product_name": "xen",
                    "version": {
                      "version_data": [
                        {
                          "version_affected": "?\u003c",
                          "version_value": "4.12"
                        },
                        {
                          "version_affected": "\u003e=",
                          "version_value": "4.13.x"
                        },
                        {
                          "version_affected": "!\u003e",
                          "version_value": "4.14.x"
                        }
                      ]
                    }
                  },
                  {
                    "product_name": "xen",
                    "version": {
                      "version_data": [
                        {
                          "version_affected": "?\u003c",
                          "version_value": "4.12"
                        },
                        {
                          "version_affected": "\u003e=",
                          "version_value": "4.11.x"
                        },
                        {
                          "version_affected": "!\u003e",
                          "version_value": "4.12.x"
                        }
                      ]
                    }
                  },
                  {
                    "product_name": "xen",
                    "version": {
                      "version_data": [
                        {
                          "version_value": "4.15.x"
                        }
                      ]
                    }
                  }
                ]
              },
              "vendor_name": "Xen"
            }
          ]
        }
      },
      "configuration": {
        "configuration_data": {
          "description": {
            "description_data": [
              {
                "lang": "eng",
                "value": "All Xen versions from 4.0 onwards are affected.  Xen versions 3.4 and\nolder are not affected.\n\nOnly x86 HVM and PVH guests permitted to use grant table version 2\ninterfaces can leverage this vulnerability.  x86 PV guests cannot\nleverage this vulnerability.  On Arm, grant table v2 use is explicitly\nunsupported."
              }
            ]
          }
        }
      },
      "credit": {
        "credit_data": {
          "description": {
            "description_data": [
              {
                "lang": "eng",
                "value": "This issue was discovered by Jan Beulich of SUSE."
              }
            ]
          }
        }
      },
      "data_format": "MITRE",
      "data_type": "CVE",
      "data_version": "4.0",
      "description": {
        "description_data": [
          {
            "lang": "eng",
            "value": "grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes."
          }
        ]
      },
      "impact": {
        "impact_data": {
          "description": {
            "description_data": [
              {
                "lang": "eng",
                "value": "A malicious guest may be able to elevate its privileges to that of the\nhost, cause host or guest Denial of Service (DoS), or cause information\nleaks."
              }
            ]
          }
        }
      },
      "problemtype": {
        "problemtype_data": [
          {
            "description": [
              {
                "lang": "eng",
                "value": "unknown"
              }
            ]
          }
        ]
      },
      "references": {
        "reference_data": [
          {
            "name": "https://xenbits.xenproject.org/xsa/advisory-379.txt",
            "refsource": "MISC",
            "url": "https://xenbits.xenproject.org/xsa/advisory-379.txt"
          },
          {
            "name": "FEDORA-2021-4f129cc0c1",
            "refsource": "FEDORA",
            "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ/"
          },
          {
            "name": "FEDORA-2021-d68ed12e46",
            "refsource": "FEDORA",
            "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2/"
          },
          {
            "name": "DSA-4977",
            "refsource": "DEBIAN",
            "url": "https://www.debian.org/security/2021/dsa-4977"
          },
          {
            "name": "FEDORA-2021-081f9bf5d2",
            "refsource": "FEDORA",
            "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID/"
          },
          {
            "name": "GLSA-202208-23",
            "refsource": "GENTOO",
            "url": "https://security.gentoo.org/glsa/202208-23"
          }
        ]
      },
      "workaround": {
        "workaround_data": {
          "description": {
            "description_data": [
              {
                "lang": "eng",
                "value": "Running only PV guests will avoid this vulnerability.\n\nSuppressing use of grant table v2 interfaces for HVM or PVH guests will\nalso avoid this vulnerability."
              }
            ]
          }
        }
      }
    },
    "nvd.nist.gov": {
      "configurations": {
        "CVE_data_version": "4.0",
        "nodes": [
          {
            "children": [],
            "cpe_match": [
              {
                "cpe23Uri": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:*:*",
                "cpe_name": [],
                "versionEndIncluding": "4.15.0",
                "versionStartIncluding": "4.0.0",
                "vulnerable": true
              }
            ],
            "operator": "OR"
          },
          {
            "children": [],
            "cpe_match": [
              {
                "cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              },
              {
                "cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              },
              {
                "cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:35:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              }
            ],
            "operator": "OR"
          },
          {
            "children": [],
            "cpe_match": [
              {
                "cpe23Uri": "cpe:2.3:o:debian:debian_linux:11.0:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              }
            ],
            "operator": "OR"
          }
        ]
      },
      "cve": {
        "CVE_data_meta": {
          "ASSIGNER": "security@xen.org",
          "ID": "CVE-2021-28697"
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "en",
              "value": "grant table v2 status pages may remain accessible after de-allocation Guest get permitted access to certain Xen-owned pages of memory. The majority of such pages remain allocated / associated with a guest for its entire lifetime. Grant table v2 status pages, however, get de-allocated when a guest switched (back) from v2 to v1. The freeing of such pages requires that the hypervisor know where in the guest these pages were mapped. The hypervisor tracks only one use within guest space, but racing requests from the guest to insert mappings of these pages may result in any of them to become mapped in multiple locations. Upon switching back from v2 to v1, the guest would then retain access to a page that was freed and perhaps re-used for other purposes."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "en",
                  "value": "CWE-362"
                }
              ]
            }
          ]
        },
        "references": {
          "reference_data": [
            {
              "name": "https://xenbits.xenproject.org/xsa/advisory-379.txt",
              "refsource": "MISC",
              "tags": [
                "Third Party Advisory"
              ],
              "url": "https://xenbits.xenproject.org/xsa/advisory-379.txt"
            },
            {
              "name": "FEDORA-2021-d68ed12e46",
              "refsource": "FEDORA",
              "tags": [
                "Mailing List",
                "Third Party Advisory"
              ],
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/FZCNPSRPGFCQRYE2BI4D4Q4SCE56ANV2/"
            },
            {
              "name": "FEDORA-2021-4f129cc0c1",
              "refsource": "FEDORA",
              "tags": [
                "Mailing List",
                "Third Party Advisory"
              ],
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/LPRVHW4J4ZCPPOHZEWP5MOJT7XDGFFPJ/"
            },
            {
              "name": "DSA-4977",
              "refsource": "DEBIAN",
              "tags": [
                "Third Party Advisory"
              ],
              "url": "https://www.debian.org/security/2021/dsa-4977"
            },
            {
              "name": "FEDORA-2021-081f9bf5d2",
              "refsource": "FEDORA",
              "tags": [
                "Mailing List",
                "Third Party Advisory"
              ],
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/2VQCFAPBNGBBAOMJZG6QBREOG5IIDZID/"
            },
            {
              "name": "GLSA-202208-23",
              "refsource": "GENTOO",
              "tags": [
                "Third Party Advisory"
              ],
              "url": "https://security.gentoo.org/glsa/202208-23"
            }
          ]
        }
      },
      "impact": {
        "baseMetricV2": {
          "acInsufInfo": false,
          "cvssV2": {
            "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,
          "severity": "MEDIUM",
          "userInteractionRequired": false
        },
        "baseMetricV3": {
          "cvssV3": {
            "attackComplexity": "LOW",
            "attackVector": "LOCAL",
            "availabilityImpact": "HIGH",
            "baseScore": 7.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "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"
          },
          "exploitabilityScore": 1.8,
          "impactScore": 5.9
        }
      },
      "lastModifiedDate": "2022-09-28T19:56Z",
      "publishedDate": "2021-08-27T19:15Z"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.