gsd-2021-29657
Vulnerability from gsd
Modified
2023-12-13 01:23
Details
arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.
Aliases
Aliases
CVE-2021-29657


To clipboard 

{
   GSD: {
      alias: "CVE-2021-29657",
      description: "arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.",
      id: "GSD-2021-29657",
      references: [
         "https://www.suse.com/security/cve/CVE-2021-29657.html",
         "https://ubuntu.com/security/CVE-2021-29657",
         "https://advisories.mageia.org/CVE-2021-29657.html",
         "https://security.archlinux.org/CVE-2021-29657",
         "https://packetstormsecurity.com/files/cve/CVE-2021-29657",
      ],
   },
   gsd: {
      metadata: {
         exploitCode: "unknown",
         remediation: "unknown",
         reportConfidence: "confirmed",
         type: "vulnerability",
      },
      osvSchema: {
         aliases: [
            "CVE-2021-29657",
         ],
         details: "arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.",
         id: "GSD-2021-29657",
         modified: "2023-12-13T01:23:36.359923Z",
         schema_version: "1.4.0",
      },
   },
   namespaces: {
      "cve.org": {
         CVE_data_meta: {
            ASSIGNER: "cve@mitre.org",
            ID: "CVE-2021-29657",
            STATE: "PUBLIC",
         },
         affects: {
            vendor: {
               vendor_data: [
                  {
                     product: {
                        product_data: [
                           {
                              product_name: "n/a",
                              version: {
                                 version_data: [
                                    {
                                       version_value: "n/a",
                                    },
                                 ],
                              },
                           },
                        ],
                     },
                     vendor_name: "n/a",
                  },
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         data_format: "MITRE",
         data_type: "CVE",
         data_version: "4.0",
         description: {
            description_data: [
               {
                  lang: "eng",
                  value: "arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.",
               },
            ],
         },
         problemtype: {
            problemtype_data: [
               {
                  description: [
                     {
                        lang: "eng",
                        value: "n/a",
                     },
                  ],
               },
            ],
         },
         references: {
            reference_data: [
               {
                  name: "http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html",
                  refsource: "MISC",
                  url: "http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html",
               },
               {
                  name: "https://bugs.chromium.org/p/project-zero/issues/detail?id=2177",
                  refsource: "MISC",
                  url: "https://bugs.chromium.org/p/project-zero/issues/detail?id=2177",
               },
               {
                  name: "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134",
                  refsource: "CONFIRM",
                  url: "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134",
               },
               {
                  name: "https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12",
                  refsource: "CONFIRM",
                  url: "https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12",
               },
               {
                  name: "https://security.netapp.com/advisory/ntap-20210902-0008/",
                  refsource: "CONFIRM",
                  url: "https://security.netapp.com/advisory/ntap-20210902-0008/",
               },
            ],
         },
      },
      "nvd.nist.gov": {
         configurations: {
            CVE_data_version: "4.0",
            nodes: [
               {
                  children: [],
                  cpe_match: [
                     {
                        cpe23Uri: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                        cpe_name: [],
                        versionEndExcluding: "5.10.28",
                        versionStartIncluding: "5.10",
                        vulnerable: true,
                     },
                     {
                        cpe23Uri: "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                        cpe_name: [],
                        versionEndExcluding: "5.11.12",
                        versionStartIncluding: "5.11",
                        vulnerable: true,
                     },
                  ],
                  operator: "OR",
               },
            ],
         },
         cve: {
            CVE_data_meta: {
               ASSIGNER: "cve@mitre.org",
               ID: "CVE-2021-29657",
            },
            data_format: "MITRE",
            data_type: "CVE",
            data_version: "4.0",
            description: {
               description_data: [
                  {
                     lang: "en",
                     value: "arch/x86/kvm/svm/nested.c in the Linux kernel before 5.11.12 has a use-after-free in which an AMD KVM guest can bypass access control on host OS MSRs when there are nested guests, aka CID-a58d9166a756. This occurs because of a TOCTOU race condition associated with a VMCB12 double fetch in nested_svm_vmrun.",
                  },
               ],
            },
            problemtype: {
               problemtype_data: [
                  {
                     description: [
                        {
                           lang: "en",
                           value: "CWE-416",
                        },
                        {
                           lang: "en",
                           value: "CWE-367",
                        },
                     ],
                  },
               ],
            },
            references: {
               reference_data: [
                  {
                     name: "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134",
                     refsource: "CONFIRM",
                     tags: [
                        "Patch",
                        "Third Party Advisory",
                     ],
                     url: "https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a58d9166a756a0f4a6618e4f593232593d6df134",
                  },
                  {
                     name: "https://bugs.chromium.org/p/project-zero/issues/detail?id=2177",
                     refsource: "MISC",
                     tags: [
                        "Exploit",
                        "Mailing List",
                        "Patch",
                        "Third Party Advisory",
                     ],
                     url: "https://bugs.chromium.org/p/project-zero/issues/detail?id=2177",
                  },
                  {
                     name: "https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12",
                     refsource: "CONFIRM",
                     tags: [
                        "Exploit",
                        "Patch",
                        "Vendor Advisory",
                     ],
                     url: "https://cdn.kernel.org/pub/linux/kernel/v5.x/ChangeLog-5.11.12",
                  },
                  {
                     name: "http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html",
                     refsource: "MISC",
                     tags: [
                        "Third Party Advisory",
                        "VDB Entry",
                     ],
                     url: "http://packetstormsecurity.com/files/163324/KVM-nested_svm_vmrun-Double-Fetch.html",
                  },
                  {
                     name: "https://security.netapp.com/advisory/ntap-20210902-0008/",
                     refsource: "CONFIRM",
                     tags: [
                        "Third Party Advisory",
                     ],
                     url: "https://security.netapp.com/advisory/ntap-20210902-0008/",
                  },
               ],
            },
         },
         impact: {
            baseMetricV2: {
               acInsufInfo: false,
               cvssV2: {
                  accessComplexity: "MEDIUM",
                  accessVector: "LOCAL",
                  authentication: "NONE",
                  availabilityImpact: "COMPLETE",
                  baseScore: 6.9,
                  confidentialityImpact: "COMPLETE",
                  integrityImpact: "COMPLETE",
                  vectorString: "AV:L/AC:M/Au:N/C:C/I:C/A:C",
                  version: "2.0",
               },
               exploitabilityScore: 3.4,
               impactScore: 10,
               obtainAllPrivilege: false,
               obtainOtherPrivilege: false,
               obtainUserPrivilege: false,
               severity: "MEDIUM",
               userInteractionRequired: false,
            },
            baseMetricV3: {
               cvssV3: {
                  attackComplexity: "HIGH",
                  attackVector: "LOCAL",
                  availabilityImpact: "HIGH",
                  baseScore: 7.4,
                  baseSeverity: "HIGH",
                  confidentialityImpact: "HIGH",
                  integrityImpact: "HIGH",
                  privilegesRequired: "NONE",
                  scope: "UNCHANGED",
                  userInteraction: "NONE",
                  vectorString: "CVSS:3.1/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
                  version: "3.1",
               },
               exploitabilityScore: 1.4,
               impactScore: 5.9,
            },
         },
         lastModifiedDate: "2023-05-19T16:51Z",
         publishedDate: "2021-07-22T17:15Z",
      },
   },
}


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