gsd-2019-18423
Vulnerability from gsd
Modified
2023-12-13 01:23
Details
An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service via a XENMEM_add_to_physmap hypercall. p2m->max_mapped_gfn is used by the functions p2m_resolve_translation_fault() and p2m_get_entry() to sanity check guest physical frame. The rest of the code in the two functions will assume that there is a valid root table and check that with BUG_ON(). The function p2m_get_root_pointer() will ignore the unused top bits of a guest physical frame. This means that the function p2m_set_entry() will alias the frame. However, p2m->max_mapped_gfn will be updated using the original frame. It would be possible to set p2m->max_mapped_gfn high enough to cover a frame that would lead p2m_get_root_pointer() to return NULL in p2m_get_entry() and p2m_resolve_translation_fault(). Additionally, the sanity check on p2m->max_mapped_gfn is off-by-one allowing "highest mapped + 1" to be considered valid. However, p2m_get_root_pointer() will return NULL. The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen version 4.8 and newer are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected.
Aliases
Aliases
CVE-2019-18423


To clipboard 

{
  "GSD": {
    "alias": "CVE-2019-18423",
    "description": "An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service via a XENMEM_add_to_physmap hypercall. p2m-\u003emax_mapped_gfn is used by the functions p2m_resolve_translation_fault() and p2m_get_entry() to sanity check guest physical frame. The rest of the code in the two functions will assume that there is a valid root table and check that with BUG_ON(). The function p2m_get_root_pointer() will ignore the unused top bits of a guest physical frame. This means that the function p2m_set_entry() will alias the frame. However, p2m-\u003emax_mapped_gfn will be updated using the original frame. It would be possible to set p2m-\u003emax_mapped_gfn high enough to cover a frame that would lead p2m_get_root_pointer() to return NULL in p2m_get_entry() and p2m_resolve_translation_fault(). Additionally, the sanity check on p2m-\u003emax_mapped_gfn is off-by-one allowing \"highest mapped + 1\" to be considered valid. However, p2m_get_root_pointer() will return NULL. The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen version 4.8 and newer are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected.",
    "id": "GSD-2019-18423",
    "references": [
      "https://www.suse.com/security/cve/CVE-2019-18423.html",
      "https://www.debian.org/security/2020/dsa-4602",
      "https://advisories.mageia.org/CVE-2019-18423.html"
    ]
  },
  "gsd": {
    "metadata": {
      "exploitCode": "unknown",
      "remediation": "unknown",
      "reportConfidence": "confirmed",
      "type": "vulnerability"
    },
    "osvSchema": {
      "aliases": [
        "CVE-2019-18423"
      ],
      "details": "An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service via a XENMEM_add_to_physmap hypercall. p2m-\u003emax_mapped_gfn is used by the functions p2m_resolve_translation_fault() and p2m_get_entry() to sanity check guest physical frame. The rest of the code in the two functions will assume that there is a valid root table and check that with BUG_ON(). The function p2m_get_root_pointer() will ignore the unused top bits of a guest physical frame. This means that the function p2m_set_entry() will alias the frame. However, p2m-\u003emax_mapped_gfn will be updated using the original frame. It would be possible to set p2m-\u003emax_mapped_gfn high enough to cover a frame that would lead p2m_get_root_pointer() to return NULL in p2m_get_entry() and p2m_resolve_translation_fault(). Additionally, the sanity check on p2m-\u003emax_mapped_gfn is off-by-one allowing \"highest mapped + 1\" to be considered valid. However, p2m_get_root_pointer() will return NULL. The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen version 4.8 and newer are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected.",
      "id": "GSD-2019-18423",
      "modified": "2023-12-13T01:23:50.422973Z",
      "schema_version": "1.4.0"
    }
  },
  "namespaces": {
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        "ASSIGNER": "cve@mitre.org",
        "ID": "CVE-2019-18423",
        "STATE": "PUBLIC"
      },
      "affects": {
        "vendor": {
          "vendor_data": [
            {
              "product": {
                "product_data": [
                  {
                    "product_name": "n/a",
                    "version": {
                      "version_data": [
                        {
                          "version_value": "n/a"
                        }
                      ]
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                ]
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              "vendor_name": "n/a"
            }
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            "value": "An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service via a XENMEM_add_to_physmap hypercall. p2m-\u003emax_mapped_gfn is used by the functions p2m_resolve_translation_fault() and p2m_get_entry() to sanity check guest physical frame. The rest of the code in the two functions will assume that there is a valid root table and check that with BUG_ON(). The function p2m_get_root_pointer() will ignore the unused top bits of a guest physical frame. This means that the function p2m_set_entry() will alias the frame. However, p2m-\u003emax_mapped_gfn will be updated using the original frame. It would be possible to set p2m-\u003emax_mapped_gfn high enough to cover a frame that would lead p2m_get_root_pointer() to return NULL in p2m_get_entry() and p2m_resolve_translation_fault(). Additionally, the sanity check on p2m-\u003emax_mapped_gfn is off-by-one allowing \"highest mapped + 1\" to be considered valid. However, p2m_get_root_pointer() will return NULL. The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen version 4.8 and newer are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected."
          }
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          {
            "name": "http://xenbits.xen.org/xsa/advisory-301.html",
            "refsource": "MISC",
            "url": "http://xenbits.xen.org/xsa/advisory-301.html"
          },
          {
            "name": "[oss-security] 20191031 Xen Security Advisory 301 v3 (CVE-2019-18423) - add-to-physmap can be abused to DoS Arm hosts",
            "refsource": "MLIST",
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          },
          {
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          },
          {
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            "refsource": "DEBIAN",
            "url": "https://www.debian.org/security/2020/dsa-4602"
          },
          {
            "name": "20200114 [SECURITY] [DSA 4602-1] xen security update",
            "refsource": "BUGTRAQ",
            "url": "https://seclists.org/bugtraq/2020/Jan/21"
          },
          {
            "name": "GLSA-202003-56",
            "refsource": "GENTOO",
            "url": "https://security.gentoo.org/glsa/202003-56"
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        ]
      }
    },
    "nvd.nist.gov": {
      "configurations": {
        "CVE_data_version": "4.0",
        "nodes": [
          {
            "children": [],
            "cpe_match": [
              {
                "cpe23Uri": "cpe:2.3:o:xen:xen:*:*:*:*:*:*:arm:*",
                "cpe_name": [],
                "versionEndIncluding": "4.12.1",
                "versionStartIncluding": "4.8",
                "vulnerable": true
              }
            ],
            "operator": "OR"
          },
          {
            "children": [],
            "cpe_match": [
              {
                "cpe23Uri": "cpe:2.3:o:debian:debian_linux:9.0:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              },
              {
                "cpe23Uri": "cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              },
              {
                "cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:29:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              },
              {
                "cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:30:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              },
              {
                "cpe23Uri": "cpe:2.3:o:fedoraproject:fedora:31:*:*:*:*:*:*:*",
                "cpe_name": [],
                "vulnerable": true
              }
            ],
            "operator": "OR"
          }
        ]
      },
      "cve": {
        "CVE_data_meta": {
          "ASSIGNER": "cve@mitre.org",
          "ID": "CVE-2019-18423"
        },
        "data_format": "MITRE",
        "data_type": "CVE",
        "data_version": "4.0",
        "description": {
          "description_data": [
            {
              "lang": "en",
              "value": "An issue was discovered in Xen through 4.12.x allowing ARM guest OS users to cause a denial of service via a XENMEM_add_to_physmap hypercall. p2m-\u003emax_mapped_gfn is used by the functions p2m_resolve_translation_fault() and p2m_get_entry() to sanity check guest physical frame. The rest of the code in the two functions will assume that there is a valid root table and check that with BUG_ON(). The function p2m_get_root_pointer() will ignore the unused top bits of a guest physical frame. This means that the function p2m_set_entry() will alias the frame. However, p2m-\u003emax_mapped_gfn will be updated using the original frame. It would be possible to set p2m-\u003emax_mapped_gfn high enough to cover a frame that would lead p2m_get_root_pointer() to return NULL in p2m_get_entry() and p2m_resolve_translation_fault(). Additionally, the sanity check on p2m-\u003emax_mapped_gfn is off-by-one allowing \"highest mapped + 1\" to be considered valid. However, p2m_get_root_pointer() will return NULL. The problem could be triggered with a specially crafted hypercall XENMEM_add_to_physmap{, _batch} followed by an access to an address (via hypercall or direct access) that passes the sanity check but cause p2m_get_root_pointer() to return NULL. A malicious guest administrator may cause a hypervisor crash, resulting in a Denial of Service (DoS). Xen version 4.8 and newer are vulnerable. Only Arm systems are vulnerable. x86 systems are not affected."
            }
          ]
        },
        "problemtype": {
          "problemtype_data": [
            {
              "description": [
                {
                  "lang": "en",
                  "value": "CWE-193"
                }
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        },
        "references": {
          "reference_data": [
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              "url": "http://xenbits.xen.org/xsa/advisory-301.html"
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            {
              "name": "[oss-security] 20191031 Xen Security Advisory 301 v3 (CVE-2019-18423) - add-to-physmap can be abused to DoS Arm hosts",
              "refsource": "MLIST",
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            },
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              ],
              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/I5WWPW4BSZDDW7VHU427XTVXV7ROOFFW/"
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              "url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/IZYATWNUGHRBG6I3TC24YHP5Y3J7I6KH/"
            },
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              "name": "GLSA-202003-56",
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              "tags": [
                "Third Party Advisory"
              ],
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            }
          ]
        }
      },
      "impact": {
        "baseMetricV2": {
          "acInsufInfo": false,
          "cvssV2": {
            "accessComplexity": "MEDIUM",
            "accessVector": "NETWORK",
            "authentication": "SINGLE",
            "availabilityImpact": "COMPLETE",
            "baseScore": 8.5,
            "confidentialityImpact": "COMPLETE",
            "integrityImpact": "COMPLETE",
            "vectorString": "AV:N/AC:M/Au:S/C:C/I:C/A:C",
            "version": "2.0"
          },
          "exploitabilityScore": 6.8,
          "impactScore": 10.0,
          "obtainAllPrivilege": false,
          "obtainOtherPrivilege": false,
          "obtainUserPrivilege": false,
          "severity": "HIGH",
          "userInteractionRequired": false
        },
        "baseMetricV3": {
          "cvssV3": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "exploitabilityScore": 2.8,
          "impactScore": 5.9
        }
      },
      "lastModifiedDate": "2023-03-29T18:21Z",
      "publishedDate": "2019-10-31T14:15Z"
    }
  }
}


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