CVE-2023-34328 (GCVE-0-2023-34328)
Vulnerability from cvelistv5
Published
2024-01-05 16:34
Modified
2025-11-04 19:16
Summary
[This CNA information record relates to multiple CVEs; the text explains which aspects/vulnerabilities correspond to which CVE.] AMD CPUs since ~2014 have extensions to normal x86 debugging functionality. Xen supports guests using these extensions. Unfortunately there are errors in Xen's handling of the guest state, leading to denials of service. 1) CVE-2023-34327 - An HVM vCPU can end up operating in the context of a previous vCPUs debug mask state. 2) CVE-2023-34328 - A PV vCPU can place a breakpoint over the live GDT. This allows the PV vCPU to exploit XSA-156 / CVE-2015-8104 and lock up the CPU entirely.
Impacted products
Show details on NVD website


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  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2025-11-04T19:16:42.078Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://xenbits.xenproject.org/xsa/advisory-444.html"
          },
          {
            "url": "http://xenbits.xen.org/xsa/advisory-444.html"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "metrics": [
          {
            "cvssV3_1": {
              "attackComplexity": "LOW",
              "attackVector": "LOCAL",
              "availabilityImpact": "HIGH",
              "baseScore": 5.5,
              "baseSeverity": "MEDIUM",
              "confidentialityImpact": "NONE",
              "integrityImpact": "NONE",
              "privilegesRequired": "LOW",
              "scope": "UNCHANGED",
              "userInteraction": "NONE",
              "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H",
              "version": "3.1"
            }
          },
          {
            "other": {
              "content": {
                "id": "CVE-2023-34328",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-05-08T17:36:49.354927Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "problemTypes": [
          {
            "descriptions": [
              {
                "description": "CWE-noinfo Not enough information",
                "lang": "en",
                "type": "CWE"
              }
            ]
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-06-03T14:41:06.224Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unknown",
          "product": "Xen",
          "vendor": "Xen",
          "versions": [
            {
              "status": "unknown",
              "version": "consult Xen advisory XSA-444"
            }
          ]
        }
      ],
      "configurations": [
        {
          "lang": "en",
          "value": "Only AMD/Hygon hardware supporting the DBEXT feature are vulnerable.\nThis is believed to be the Steamroller microarchitecture and later.\n\nFor CVE-2023-34327, Xen versions 4.5 and later are vulnerable.\n\nFor CVE-2023-34328, Xen version between 4.5 and 4.13 are vulnerable.\nThe issue is benign in Xen 4.14 and later owing to an unrelated change.\n"
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "finder",
          "value": "This issue was discovered by Andrew Cooper of XenServer.\n"
        }
      ],
      "datePublic": "2023-10-10T12:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "\n[This CNA information record relates to multiple CVEs; the\ntext explains which aspects/vulnerabilities correspond to which CVE.]\n\nAMD CPUs since ~2014 have extensions to normal x86 debugging functionality.\nXen supports guests using these extensions.\n\nUnfortunately there are errors in Xen\u0027s handling of the guest state, leading\nto denials of service.\n\n 1) CVE-2023-34327 - An HVM vCPU can end up operating in the context of\n    a previous vCPUs debug mask state.\n\n 2) CVE-2023-34328 - A PV vCPU can place a breakpoint over the live GDT.\n    This allows the PV vCPU to exploit XSA-156 / CVE-2015-8104 and lock\n    up the CPU entirely.\n"
        }
      ],
      "impacts": [
        {
          "descriptions": [
            {
              "lang": "en",
              "value": "For CVE-2023-34327, any guest (PV or HVM) using Debug Masks normally for\nit\u0027s own purposes can cause incorrect behaviour in an unrelated HVM\nvCPU, most likely resulting in a guest crash.\n\nFor CVE-2023-34328, a buggy or malicious PV guest kernel can lock up the\nhost.\n"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2024-01-05T16:34:11.100Z",
        "orgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
        "shortName": "XEN"
      },
      "references": [
        {
          "url": "https://xenbits.xenproject.org/xsa/advisory-444.html"
        }
      ],
      "title": "x86/AMD: Debug Mask handling",
      "workarounds": [
        {
          "lang": "en",
          "value": "For CVE-2023-34327, HVM VMs which can see the DBEXT feature are not\nsusceptible to running in the wrong state.  By default, VMs will see the\nDBEXT feature on capable hardware, and when not explicitly levelled for\nmigration compatibility.\n\nFor CVE-2023-34328, PV VMs which cannot see the DBEXT feature cannot\nleverage the vulnerability.\n"
        }
      ]
    }
  },
  "cveMetadata": {
    "assignerOrgId": "23aa2041-22e1-471f-9209-9b7396fa234f",
    "assignerShortName": "XEN",
    "cveId": "CVE-2023-34328",
    "datePublished": "2024-01-05T16:34:11.100Z",
    "dateReserved": "2023-06-01T10:44:17.066Z",
    "dateUpdated": "2025-11-04T19:16:42.078Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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