CVE-2023-53769 (GCVE-0-2023-53769)
Vulnerability from cvelistv5
Published
2025-12-08 01:19
Modified
2026-08-05 09:15
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: virt/coco/sev-guest: Double-buffer messages The encryption algorithms read and write directly to shared unencrypted memory, which may leak information as well as permit the host to tamper with the message integrity. Instead, copy whole messages in or out as needed before doing any computation on them.
References
Impacted products
Vendor Product Version
Linux Linux Version: d5af44dde5461d125d1602ac913ab5c6bdf09b8b
Version: d5af44dde5461d125d1602ac913ab5c6bdf09b8b
Version: d5af44dde5461d125d1602ac913ab5c6bdf09b8b
Version: d5af44dde5461d125d1602ac913ab5c6bdf09b8b
 Create a notification for this product.
Show details on NVD website

To clipboard 

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/virt/coco/sev-guest/sev-guest.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "577a64725bfd77645986168e953d405067ee565b",
              "status": "affected",
              "version": "d5af44dde5461d125d1602ac913ab5c6bdf09b8b",
              "versionType": "git"
            },
            {
              "lessThan": "c27dafc4aa50a29ec927b3aa84ac7b430071f682",
              "status": "affected",
              "version": "d5af44dde5461d125d1602ac913ab5c6bdf09b8b",
              "versionType": "git"
            },
            {
              "lessThan": "4b69c63f716cfda38e1210e65b68f67f6cee2ddf",
              "status": "affected",
              "version": "d5af44dde5461d125d1602ac913ab5c6bdf09b8b",
              "versionType": "git"
            },
            {
              "lessThan": "965006103a14703cc42043bbf9b5e0cdf7a468ad",
              "status": "affected",
              "version": "d5af44dde5461d125d1602ac913ab5c6bdf09b8b",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/virt/coco/sev-guest/sev-guest.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.19"
            },
            {
              "lessThan": "5.19",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.28",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.2.*",
              "status": "unaffected",
              "version": "6.2.15",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.3.*",
              "status": "unaffected",
              "version": "6.3.2",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.4",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.28",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.2.15",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.3.2",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.4",
                  "versionStartIncluding": "5.19",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nvirt/coco/sev-guest: Double-buffer messages\n\nThe encryption algorithms read and write directly to shared unencrypted\nmemory, which may leak information as well as permit the host to tamper\nwith the message integrity. Instead, copy whole messages in or out as\nneeded before doing any computation on them."
        }
      ],
      "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 adversary is the untrusted hypervisor, which attacks the guest kernel through the local shared-memory/VMGEXIT interface (host-writable `set_memory_decrypted()` pages), not via the network stack. This is the standard AV:L mapping for hypervisor-to-confidential-guest attacks.\nAC:L - The replay/tamper attack requires no race at all \u2014 the host rewrites both shared headers while the vCPU is descheduled after the VMGEXIT \u2014 and for the `msg_sz` TOCTOU the hypervisor fully controls guest scheduling (APIC-timer preemption, NPT-fault single-stepping, concurrent writes from another core), so it wins the check-vs-use window deterministically.\nPR:N - SEV-SNP\u0027s entire security premise is that the hypervisor holds zero privilege within the guest\u0027s security authority, so the attacker needs no credentials in the vulnerable component; it only waits for the attestation request that every SNP guest issues automatically at boot, or forces one by resetting the guest.\nUI:N - No human user must act \u2014 the guest request is issued by automated attestation/disk-unlock agents during normal boot, and the host can induce it at will by rebooting the VM.\nS:C - Exploitation breaches the hardware-enforced SEV-SNP boundary, giving a distinct security authority (the hypervisor) read and write reach into guest-protected resources, and a replayed attestation report additionally deceives a third-party remote verifier into releasing secrets \u2014 impact well beyond the vulnerable driver\u0027s own scope.\nC:H - The commit states outright that performing crypto directly in shared memory \"may leak information,\" exposing guest secrets including `SNP_GET_DERIVED_KEY` material used to seal guest disk-encryption keys; the `msg_sz` TOCTOU additionally drags ~64 KB of adjacent private guest memory through the cipher and yields heap corruption leverageable for further disclosure.\nI:H - The host controls both sides of the sequence-number comparison and the decryption IV, letting it replay stale authenticated attestation and derived-key responses and thereby defeat attestation entirely; the `msg_sz` TOCTOU is additionally a length-controlled out-of-bounds write of up to ~64 KB into a kmalloc\u0027d buffer and into an 80-byte on-stack buffer in `get_derived_key()`.\nA:H - The out-of-bounds GCM write overruns the 16 KB guest kernel stack by up to ~64 KB (and smashes the slab in the report paths), guaranteeing a guest kernel panic; failure paths also invoke `snp_disable_vmpck()`, permanently zeroing the VMPCK and killing attestation for the VM\u0027s lifetime."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T09:15:56.461Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/577a64725bfd77645986168e953d405067ee565b"
        },
        {
          "url": "https://git.kernel.org/stable/c/c27dafc4aa50a29ec927b3aa84ac7b430071f682"
        },
        {
          "url": "https://git.kernel.org/stable/c/4b69c63f716cfda38e1210e65b68f67f6cee2ddf"
        },
        {
          "url": "https://git.kernel.org/stable/c/965006103a14703cc42043bbf9b5e0cdf7a468ad"
        }
      ],
      "title": "virt/coco/sev-guest: Double-buffer messages",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2023-53769",
    "datePublished": "2025-12-08T01:19:32.417Z",
    "dateReserved": "2025-12-08T01:18:04.281Z",
    "dateUpdated": "2026-08-05T09:15:56.461Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • 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.