Vulnerability-Lookup

FKIE_CVE-2023-53996

Vulnerability from fkie_nvd - Published: 2025-12-24 11:15 - Updated: 2026-08-04 10:19

Severity

9.3 (Critical) - CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Summary

In the Linux kernel, the following vulnerability has been resolved: x86/sev: Make enc_dec_hypercall() accept a size instead of npages enc_dec_hypercall() accepted a page count instead of a size, which forced its callers to round up. As a result, non-page aligned vaddrs caused pages to be spuriously marked as decrypted via the encryption status hypercall, which in turn caused consistent corruption of pages during live migration. Live migration requires accurate encryption status information to avoid migrating pages from the wrong perspective.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/6615212d8e131b45bd9705b0d69cc0d2f624666f
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/8ae7457e71a320867d868f2622d7c643596e4f43
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ac3f9c9f1b37edaa7d1a9b908bc79d843955a1a2
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/ba50e7773a99a109a1ea6f753b766a080d3b21cc

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/include/asm/mem_encrypt.h",
            "arch/x86/kernel/kvm.c",
            "arch/x86/mm/mem_encrypt_amd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ba50e7773a99a109a1ea6f753b766a080d3b21cc",
              "status": "affected",
              "version": "064ce6c550a0630789978bfec7a13ab2bd1bdcdf",
              "versionType": "git"
            },
            {
              "lessThan": "6615212d8e131b45bd9705b0d69cc0d2f624666f",
              "status": "affected",
              "version": "064ce6c550a0630789978bfec7a13ab2bd1bdcdf",
              "versionType": "git"
            },
            {
              "lessThan": "8ae7457e71a320867d868f2622d7c643596e4f43",
              "status": "affected",
              "version": "064ce6c550a0630789978bfec7a13ab2bd1bdcdf",
              "versionType": "git"
            },
            {
              "lessThan": "ac3f9c9f1b37edaa7d1a9b908bc79d843955a1a2",
              "status": "affected",
              "version": "064ce6c550a0630789978bfec7a13ab2bd1bdcdf",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/include/asm/mem_encrypt.h",
            "arch/x86/kernel/kvm.c",
            "arch/x86/mm/mem_encrypt_amd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.16"
            },
            {
              "lessThan": "5.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.4.*",
              "status": "unaffected",
              "version": "6.4.16",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.5.*",
              "status": "unaffected",
              "version": "6.5.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.6",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/sev: Make enc_dec_hypercall() accept a size instead of npages\n\nenc_dec_hypercall() accepted a page count instead of a size, which\nforced its callers to round up. As a result, non-page aligned\nvaddrs caused pages to be spuriously marked as decrypted via the\nencryption status hypercall, which in turn caused consistent\ncorruption of pages during live migration. Live migration requires\naccurate encryption status information to avoid migrating pages\nfrom the wrong perspective."
    }
  ],
  "id": "CVE-2023-53996",
  "lastModified": "2026-08-04T10:19:25.110",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 9.3,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.5,
        "impactScore": 6.0,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2025-12-24T11:15:52.507",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6615212d8e131b45bd9705b0d69cc0d2f624666f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/8ae7457e71a320867d868f2622d7c643596e4f43"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ac3f9c9f1b37edaa7d1a9b908bc79d843955a1a2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/ba50e7773a99a109a1ea6f753b766a080d3b21cc"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Deferred"
}

CVE-2023-53996 (GCVE-0-2023-53996)

Vulnerability from cvelistv5 – Published: 2025-12-24 10:55 – Updated: 2026-08-05 09:16

Title

x86/sev: Make enc_dec_hypercall() accept a size instead of npages

Summary

Severity

9.3 (Critical)


                        
                          CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H

Assigner

Linux CNA under the mitre root

CNA scorecard D 53/100 over 7033 records in the last 180 days details

References

4 references

URL	Tags
https://git.kernel.org/stable/c/ba50e7773a99a109a…
https://git.kernel.org/stable/c/6615212d8e131b45b…
https://git.kernel.org/stable/c/8ae7457e71a320867…
https://git.kernel.org/stable/c/ac3f9c9f1b37edaa7…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 064ce6c550a0630789978bfec7a13ab2bd1bdcdf , < ba50e7773a99a109a1ea6f753b766a080d3b21cc (git) Affected: 064ce6c550a0630789978bfec7a13ab2bd1bdcdf , < 6615212d8e131b45bd9705b0d69cc0d2f624666f (git) Affected: 064ce6c550a0630789978bfec7a13ab2bd1bdcdf , < 8ae7457e71a320867d868f2622d7c643596e4f43 (git) Affected: 064ce6c550a0630789978bfec7a13ab2bd1bdcdf , < ac3f9c9f1b37edaa7d1a9b908bc79d843955a1a2 (git)
Linux	Linux	Affected: 5.16 Unaffected: 0 , < 5.16 (semver) Unaffected: 6.1.53 , ≤ 6.1.* (semver) Unaffected: 6.4.16 , ≤ 6.4.* (semver) Unaffected: 6.5.3 , ≤ 6.5.* (semver) Unaffected: 6.6 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/include/asm/mem_encrypt.h",
            "arch/x86/kernel/kvm.c",
            "arch/x86/mm/mem_encrypt_amd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "ba50e7773a99a109a1ea6f753b766a080d3b21cc",
              "status": "affected",
              "version": "064ce6c550a0630789978bfec7a13ab2bd1bdcdf",
              "versionType": "git"
            },
            {
              "lessThan": "6615212d8e131b45bd9705b0d69cc0d2f624666f",
              "status": "affected",
              "version": "064ce6c550a0630789978bfec7a13ab2bd1bdcdf",
              "versionType": "git"
            },
            {
              "lessThan": "8ae7457e71a320867d868f2622d7c643596e4f43",
              "status": "affected",
              "version": "064ce6c550a0630789978bfec7a13ab2bd1bdcdf",
              "versionType": "git"
            },
            {
              "lessThan": "ac3f9c9f1b37edaa7d1a9b908bc79d843955a1a2",
              "status": "affected",
              "version": "064ce6c550a0630789978bfec7a13ab2bd1bdcdf",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "arch/x86/include/asm/mem_encrypt.h",
            "arch/x86/kernel/kvm.c",
            "arch/x86/mm/mem_encrypt_amd.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.16"
            },
            {
              "lessThan": "5.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.4.*",
              "status": "unaffected",
              "version": "6.4.16",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.5.*",
              "status": "unaffected",
              "version": "6.5.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.6",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.53",
                  "versionStartIncluding": "5.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.4.16",
                  "versionStartIncluding": "5.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.5.3",
                  "versionStartIncluding": "5.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.6",
                  "versionStartIncluding": "5.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nx86/sev: Make enc_dec_hypercall() accept a size instead of npages\n\nenc_dec_hypercall() accepted a page count instead of a size, which\nforced its callers to round up. As a result, non-page aligned\nvaddrs caused pages to be spuriously marked as decrypted via the\nencryption status hypercall, which in turn caused consistent\ncorruption of pages during live migration. Live migration requires\naccurate encryption status information to avoid migrating pages\nfrom the wrong perspective."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.3,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The defective code is guest `__init` code in `arch/x86/mm/mem_encrypt_amd.c` and the damage is delivered by hypervisor-side memory/migration operations on the same physical host; no network protocol data reaches the vulnerable function. This matches the AV:L scoring of comparable guest-side x86/sev confidential-computing flaws.\nAC:L - The mis-reporting is deterministic \u2014 the percpu variables passed to `early_set_memory_decrypted()` are always non-page-aligned, so the extra page is spuriously declared shared on every SEV guest boot, and the commit explicitly describes \"consistent corruption\" with no race or memory-layout luck involved. The party that triggers the damaging step (live migration) controls it completely.\nPR:N - No privileges of any kind are required inside the guest \u2014 the wrong encryption status is registered during early boot and the corruption lands during a routine, guest-transparent live migration. In the SEV threat model the untrusted hypervisor needs no guest credentials to reach this state.\nUI:N - Live migration is transparent to the guest and requires no action by any guest user; the mis-declaration itself happens automatically at boot.\nS:C - The guest kernel bug corrupts state held by a different security authority \u2014 the hypervisor\u0027s page-encryption-status list \u2014 causing memory protected by the SEV/AMD-SP confidential-computing boundary to be handled by the host as shared. The impact therefore crosses the guest/host CoCo boundary rather than staying within the guest\u0027s own authority.\nC:H - Pages containing guest-private kernel data are declared shared to the untrusted hypervisor, so they are handled outside the SEV-protected migration path (raw-copied across the migration channel rather than PSP-wrapped) and the host treats them as memory it may freely read. Wholesale corruption of kernel percpu pages is also leverageable toward disclosure.\nI:H - The commit documents consistent corruption of entire guest kernel pages during live migration, and the mis-marked private pages are additionally exposed to host writes as \"shared\" memory \u2014 a direct integrity break of guest-private memory.\nA:H - The corrupted pages sit in the kernel percpu region adjacent to `apf_reason`/`steal_time`/`kvm_apic_eoi`; consuming pseudorandom garbage there after migration reliably leads to kernel oops/panic and an unusable guest."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T09:16:33.065Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/ba50e7773a99a109a1ea6f753b766a080d3b21cc"
        },
        {
          "url": "https://git.kernel.org/stable/c/6615212d8e131b45bd9705b0d69cc0d2f624666f"
        },
        {
          "url": "https://git.kernel.org/stable/c/8ae7457e71a320867d868f2622d7c643596e4f43"
        },
        {
          "url": "https://git.kernel.org/stable/c/ac3f9c9f1b37edaa7d1a9b908bc79d843955a1a2"
        }
      ],
      "title": "x86/sev: Make enc_dec_hypercall() accept a size instead of npages",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2023-53996",
    "datePublished": "2025-12-24T10:55:33.402Z",
    "dateReserved": "2025-12-24T10:53:46.176Z",
    "dateUpdated": "2026-08-05T09:16:33.065Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

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.

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
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