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CVE-2023-53751 (GCVE-0-2023-53751)

Vulnerability from cvelistv5 – Published: 2025-12-08 01:19 – Updated: 2026-08-05 09:15
VLAI
Title
cifs: fix potential use-after-free bugs in TCP_Server_Info::hostname
Summary
In the Linux kernel, the following vulnerability has been resolved: cifs: fix potential use-after-free bugs in TCP_Server_Info::hostname TCP_Server_Info::hostname may be updated once or many times during reconnect, so protect its access outside reconnect path as well and then prevent any potential use-after-free bugs.
Severity
9.8 (Critical)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Assigner
References
Impacted products
Vendor Product Version CPE status
Linux Linux Affected: 93d5cb517db39e8af8d1292f9e785e4983b7f708 , < 64d62ac6d6514cba1305bd08e271ec1843bdd612 (git)
Affected: 93d5cb517db39e8af8d1292f9e785e4983b7f708 , < c511954bf142fe1995aec3c739a9f1a76990283a (git)
Affected: 93d5cb517db39e8af8d1292f9e785e4983b7f708 , < 0b08c4c499200be67d54c439d56e5ea866869945 (git)
Affected: 93d5cb517db39e8af8d1292f9e785e4983b7f708 , < 90c49fce1c43e1cc152695e20363ff5087897c09 (git)
guessed Create a notification for this product.
Linux Linux Affected: 5.0
Unaffected: 0 , < 5.0 (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
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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/cifs/cifs_debug.c",
            "fs/cifs/cifs_debug.h",
            "fs/cifs/connect.c",
            "fs/cifs/sess.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "64d62ac6d6514cba1305bd08e271ec1843bdd612",
              "status": "affected",
              "version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
              "versionType": "git"
            },
            {
              "lessThan": "c511954bf142fe1995aec3c739a9f1a76990283a",
              "status": "affected",
              "version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
              "versionType": "git"
            },
            {
              "lessThan": "0b08c4c499200be67d54c439d56e5ea866869945",
              "status": "affected",
              "version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
              "versionType": "git"
            },
            {
              "lessThan": "90c49fce1c43e1cc152695e20363ff5087897c09",
              "status": "affected",
              "version": "93d5cb517db39e8af8d1292f9e785e4983b7f708",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/cifs/cifs_debug.c",
            "fs/cifs/cifs_debug.h",
            "fs/cifs/connect.c",
            "fs/cifs/sess.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.0"
            },
            {
              "lessThan": "5.0",
              "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": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.2.15",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.3.2",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.4",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ncifs: fix potential use-after-free bugs in TCP_Server_Info::hostname\n\nTCP_Server_Info::hostname may be updated once or many times during\nreconnect, so protect its access outside reconnect path as well and\nthen prevent any potential use-after-free bugs."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 9.8,
            "baseSeverity": "CRITICAL",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:N - The vulnerability is in the CIFS/SMB client\u0027s handling of remote server data \u2014 the freed/reallocated `hostname` is derived from server-supplied DFS referral targets, and both the free side (forced reconnects) and the read side (error-path `cifs_server_dbg(VFS,...)` on malformed or bad-signature responses) are driven entirely by a remote SMB peer or an on-path network attacker.\nAC:L - The attacker controls both sides of the race: it can force unlimited reconnect cycles by dropping the TCP connection, chooses DFS target names so it controls the size and content of the freed/reallocated string for heap grooming, and can trigger the unlocked readers on demand via malformed responses, with unlimited retries.\nPR:N - No credentials or privileges on the target are required \u2014 the attacker is the remote SMB server or a network attacker, and the reader side is additionally reachable by any unprivileged local user through the world-readable (0444) /proc/fs/cifs/DebugData and 0644 /proc/fs/cifs/Stats.\nUI:N - Against a host with an already-established DFS CIFS mount (routine on enterprise servers and appliances), the attacker triggers reconnects and error paths on its own; no action by any user is needed at attack time.\nS:U - The use-after-free is in kernel memory and its impact stays within the kernel\u0027s own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - `seq_printf(\"%s\", server-\u003ehostname)` on the dangling pointer copies freed heap memory into the world-readable /proc/fs/cifs/DebugData output, reading until an arbitrary NUL byte, giving an unbounded kernel heap disclosure whose contents the attacker can groom; the same data also leaks to dmesg via `cifs_server_dbg`.\nI:H - This is a use-after-free on an attacker-size-controlled slab object with a racing free/reassign of the same pointer, which enables heap spraying and reclaim of the freed slot; per kernel UAF scoring this is treated as exploitable for control-flow/memory corruption.\nA:H - Dereferencing the freed string over poisoned, unmapped, or reallocated memory produces a kernel oops/panic, and the attacker can repeat the reconnect-driven race indefinitely."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T09:15:47.928Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/64d62ac6d6514cba1305bd08e271ec1843bdd612"
        },
        {
          "url": "https://git.kernel.org/stable/c/c511954bf142fe1995aec3c739a9f1a76990283a"
        },
        {
          "url": "https://git.kernel.org/stable/c/0b08c4c499200be67d54c439d56e5ea866869945"
        },
        {
          "url": "https://git.kernel.org/stable/c/90c49fce1c43e1cc152695e20363ff5087897c09"
        }
      ],
      "title": "cifs: fix potential use-after-free bugs in TCP_Server_Info::hostname",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2023-53751",
    "datePublished": "2025-12-08T01:19:11.160Z",
    "dateReserved": "2025-12-08T01:18:04.279Z",
    "dateUpdated": "2026-08-05T09:15:47.928Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "epss": {
      "cve": "CVE-2023-53751",
      "date": "2026-09-16",
      "epss": "0.00415",
      "percentile": "0.35195"
    },
    "nvd": "{\"cve\":{\"id\":\"CVE-2023-53751\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-12-08T02:15:50.590\",\"lastModified\":\"2026-08-04T10:19:19.813\",\"vulnStatus\":\"Deferred\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\ncifs: fix potential use-after-free bugs in TCP_Server_Info::hostname\\n\\nTCP_Server_Info::hostname may be updated once or many times during\\nreconnect, so protect its access outside reconnect path as well and\\nthen prevent any potential use-after-free bugs.\"}],\"affected\":[{\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"affectedData\":[{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"unaffected\",\"programFiles\":[\"fs/cifs/cifs_debug.c\",\"fs/cifs/cifs_debug.h\",\"fs/cifs/connect.c\",\"fs/cifs/sess.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"93d5cb517db39e8af8d1292f9e785e4983b7f708\",\"lessThan\":\"64d62ac6d6514cba1305bd08e271ec1843bdd612\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"93d5cb517db39e8af8d1292f9e785e4983b7f708\",\"lessThan\":\"c511954bf142fe1995aec3c739a9f1a76990283a\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"93d5cb517db39e8af8d1292f9e785e4983b7f708\",\"lessThan\":\"0b08c4c499200be67d54c439d56e5ea866869945\",\"versionType\":\"git\",\"status\":\"affected\"},{\"version\":\"93d5cb517db39e8af8d1292f9e785e4983b7f708\",\"lessThan\":\"90c49fce1c43e1cc152695e20363ff5087897c09\",\"versionType\":\"git\",\"status\":\"affected\"}]},{\"vendor\":\"Linux\",\"product\":\"Linux\",\"defaultStatus\":\"affected\",\"programFiles\":[\"fs/cifs/cifs_debug.c\",\"fs/cifs/cifs_debug.h\",\"fs/cifs/connect.c\",\"fs/cifs/sess.c\"],\"repo\":\"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\"versions\":[{\"version\":\"5.0\",\"status\":\"affected\"},{\"version\":\"0\",\"lessThan\":\"5.0\",\"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:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H\",\"baseScore\":9.8,\"baseSeverity\":\"CRITICAL\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"HIGH\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"HIGH\"},\"exploitabilityScore\":3.9,\"impactScore\":5.9}]},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/0b08c4c499200be67d54c439d56e5ea866869945\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/64d62ac6d6514cba1305bd08e271ec1843bdd612\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/90c49fce1c43e1cc152695e20363ff5087897c09\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/c511954bf142fe1995aec3c739a9f1a76990283a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}",
    "redhat_vex": {
      "aggregate_severity": "Moderate",
      "current_release_date": "2026-08-04T19:15:01+00:00",
      "cve": "CVE-2023-53751",
      "id": "CVE-2023-53751",
      "initial_release_date": "2023-01-01T00:00:00+00:00",
      "product_status:fixed": "1057",
      "product_status:known_affected": "49",
      "product_status:known_not_affected": "107",
      "source": "Red Hat CSAF VEX",
      "status": "final",
      "title": "kernel: Linux kernel (CIFS): Use-after-free vulnerability allows data integrity compromise and denial of service",
      "url": "https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-53751.json",
      "version": "3"
    },
    "suse_vex": {
      "aggregate_severity": "moderate",
      "current_release_date": "2026-08-29T02:05:13Z",
      "cve": "CVE-2023-53751",
      "id": "CVE-2023-53751",
      "initial_release_date": "2025-12-09T00:29:18Z",
      "product_status:known_affected": "554",
      "product_status:known_not_affected": "169",
      "product_status:recommended": "268",
      "source": "SUSE CSAF VEX",
      "status": "interim",
      "title": "SUSE CVE CVE-2023-53751",
      "url": "https://ftp.suse.com/pub/projects/security/csaf-vex/cve-2023-53751.json",
      "version": "32"
    }
  }
}



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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

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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.


Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.