GCVE Workshop - 22 September 2026 (14:00-18:00), Luxembourg Before The Vulnopticon Conference - Registration

CVE-2023-53769 (GCVE-0-2023-53769)

Vulnerability from cvelistv5 – Published: 2025-12-08 01:19 – Updated: 2026-08-05 09:15
VLAI
Title
virt/coco/sev-guest: Double-buffer messages
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.
Severity
9.3 (Critical)
CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: d5af44dde5461d125d1602ac913ab5c6bdf09b8b , < 577a64725bfd77645986168e953d405067ee565b (git)
Affected: d5af44dde5461d125d1602ac913ab5c6bdf09b8b , < c27dafc4aa50a29ec927b3aa84ac7b430071f682 (git)
Affected: d5af44dde5461d125d1602ac913ab5c6bdf09b8b , < 4b69c63f716cfda38e1210e65b68f67f6cee2ddf (git)
Affected: d5af44dde5461d125d1602ac913ab5c6bdf09b8b , < 965006103a14703cc42043bbf9b5e0cdf7a468ad (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.19
Unaffected: 0 , < 5.19 (semver)
Unaffected: 6.1.28 , ≤ 6.1.* (semver)
Unaffected: 6.2.15 , ≤ 6.2.* (semver)
Unaffected: 6.3.2 , ≤ 6.3.* (semver)
Unaffected: 6.4 , ≤ * (original_commit_for_fix)
guessed 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",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2023-53769",
      "date": "2026-09-13",
      "epss": "0.00101",
      "percentile": "0.00996"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2023-53769\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-12-08T02:15:52.920\",\"lastModified\":\"2026-08-04T10:19:20.820\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"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.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"drivers/virt/coco/sev-guest/sev-guest.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"d5af44dde5461d125d1602ac913ab5c6bdf09b8b\",\"lessThan\":\"577a64725bfd77645986168e953d405067ee565b\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"d5af44dde5461d125d1602ac913ab5c6bdf09b8b\",\"lessThan\":\"c27dafc4aa50a29ec927b3aa84ac7b430071f682\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"d5af44dde5461d125d1602ac913ab5c6bdf09b8b\",\"lessThan\":\"4b69c63f716cfda38e1210e65b68f67f6cee2ddf\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"d5af44dde5461d125d1602ac913ab5c6bdf09b8b\",\"lessThan\":\"965006103a14703cc42043bbf9b5e0cdf7a468ad\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"drivers/virt/coco/sev-guest/sev-guest.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.19\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.19\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.1.28\",\"lessThanOrEqual\":\"6.1.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.2.15\",\"lessThanOrEqual\":\"6.2.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.3.2\",\"lessThanOrEqual\":\"6.3.*\",\"versionType\":\"semver\",\"status\":\"unaffected\"},{\"version\":\"6.4\",\"lessThanOrEqual\":\"*\",\"versionType\":\"original_commit_for_fix\",\"status\":\"unaffected\"}]}]}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H\",\"baseScore\":9.3,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"LOCAL\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"CHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":2.5,\"impactScore\":6.0}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/4b69c63f716cfda38e1210e65b68f67f6cee2ddf\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/577a64725bfd77645986168e953d405067ee565b\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/965006103a14703cc42043bbf9b5e0cdf7a468ad\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c27dafc4aa50a29ec927b3aa84ac7b430071f682\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-04T19:15:36+00:00",
      "cve": "CVE-2023-53769",
      "id": "CVE-2023-53769",
      "initial_release_date": "2023-01-01T00:00:00+00:00",
      "product_status:fixed": "321",
      "product_status:known_affected": "38",
      "product_status:known_not_affected": "118",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: virt/coco/sev-guest: Double-buffer messages",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-53769.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-31T00:55:49Z",
      "cve": "CVE-2023-53769",
      "id": "CVE-2023-53769",
      "initial_release_date": "2025-12-09T00:28:53Z",
      "product_status:known_affected": "435",
      "product_status:known_not_affected": "387",
      "product_status:recommended": "134",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2023-53769",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2023-53769.json",
      "version": "16"
    }
  }
}



Log in or create an account to share your comment.




Tags
Taxonomy of the tags.





Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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.


Detection rules are retrieved from Rulezet.