Vulnerability-Lookup

GHSA-C5C6-FJ3H-JWH2

Vulnerability from github – Published: 2025-12-30 15:30 – Updated: 2026-08-04 12:34

Details

In the Linux kernel, the following vulnerability has been resolved:

Bluetooth: L2CAP: Fix potential user-after-free

This fixes all instances of which requires to allocate a buffer calling alloc_skb which may release the chan lock and reacquire later which makes it possible that the chan is disconnected in the meantime.

Severity

8.8 (High)


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

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{
  "affected": [],
  "aliases": [
    "CVE-2023-54214"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-12-30T13:16:09Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: Fix potential user-after-free\n\nThis fixes all instances of which requires to allocate a buffer calling\nalloc_skb which may release the chan lock and reacquire later which\nmakes it possible that the chan is disconnected in the meantime.",
  "id": "GHSA-c5c6-fj3h-jwh2",
  "modified": "2026-08-04T12:34:48Z",
  "published": "2025-12-30T15:30:31Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-54214"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/31a288a4df7f6a28e65da22a4ab2add4a963738e"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/60aaccf16d1e099c16bebfb96428ae762cb528f7"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/64e28ecf44e46de9f01915a4146706a21c3469d2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/994e3e18908f5c4a12d07b44018e6aa85f071048"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a6a7d1541fefddf7ca0cfb34c1bff63ff809cc49"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b2fde8cb2a25125111f2144604e0e7c0ebcc4bba"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b8ed41cc04fb74005aa51d17865ca3d022760335"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/df5703348813235874d851934e957c3723d71644"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}

CVE-2023-54214 (GCVE-0-2023-54214)

Vulnerability from cvelistv5 – Published: 2025-12-30 12:11 – Updated: 2026-08-05 09:18

Title

Bluetooth: L2CAP: Fix potential user-after-free

Summary

In the Linux kernel, the following vulnerability has been resolved: Bluetooth: L2CAP: Fix potential user-after-free This fixes all instances of which requires to allocate a buffer calling alloc_skb which may release the chan lock and reacquire later which makes it possible that the chan is disconnected in the meantime.

Severity

8.8 (High)


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

Assigner

Linux mitre root

References

8 references

URL	Tags
https://git.kernel.org/stable/c/b2fde8cb2a2512511…
https://git.kernel.org/stable/c/a6a7d1541fefddf7c…
https://git.kernel.org/stable/c/60aaccf16d1e099c1…
https://git.kernel.org/stable/c/b8ed41cc04fb74005…
https://git.kernel.org/stable/c/31a288a4df7f6a28e…
https://git.kernel.org/stable/c/64e28ecf44e46de9f…
https://git.kernel.org/stable/c/994e3e18908f5c4a1…
https://git.kernel.org/stable/c/df570334881323587…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: a6a5568c03c4805d4d250f6bd9d468eeeb4ea059 , < b2fde8cb2a25125111f2144604e0e7c0ebcc4bba (git) Affected: a6a5568c03c4805d4d250f6bd9d468eeeb4ea059 , < a6a7d1541fefddf7ca0cfb34c1bff63ff809cc49 (git) Affected: a6a5568c03c4805d4d250f6bd9d468eeeb4ea059 , < 60aaccf16d1e099c16bebfb96428ae762cb528f7 (git) Affected: a6a5568c03c4805d4d250f6bd9d468eeeb4ea059 , < b8ed41cc04fb74005aa51d17865ca3d022760335 (git) Affected: a6a5568c03c4805d4d250f6bd9d468eeeb4ea059 , < 31a288a4df7f6a28e65da22a4ab2add4a963738e (git) Affected: a6a5568c03c4805d4d250f6bd9d468eeeb4ea059 , < 64e28ecf44e46de9f01915a4146706a21c3469d2 (git) Affected: a6a5568c03c4805d4d250f6bd9d468eeeb4ea059 , < 994e3e18908f5c4a12d07b44018e6aa85f071048 (git) Affected: a6a5568c03c4805d4d250f6bd9d468eeeb4ea059 , < df5703348813235874d851934e957c3723d71644 (git)
Linux	Linux	Affected: 3.5 Unaffected: 0 , < 3.5 (semver) Unaffected: 4.14.308 , ≤ 4.14.* (semver) Unaffected: 4.19.276 , ≤ 4.19.* (semver) Unaffected: 5.4.235 , ≤ 5.4.* (semver) Unaffected: 5.10.173 , ≤ 5.10.* (semver) Unaffected: 5.15.99 , ≤ 5.15.* (semver) Unaffected: 6.1.16 , ≤ 6.1.* (semver) Unaffected: 6.2.3 , ≤ 6.2.* (semver) Unaffected: 6.3 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/bluetooth/l2cap_core.c",
            "net/bluetooth/l2cap_sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "b2fde8cb2a25125111f2144604e0e7c0ebcc4bba",
              "status": "affected",
              "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059",
              "versionType": "git"
            },
            {
              "lessThan": "a6a7d1541fefddf7ca0cfb34c1bff63ff809cc49",
              "status": "affected",
              "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059",
              "versionType": "git"
            },
            {
              "lessThan": "60aaccf16d1e099c16bebfb96428ae762cb528f7",
              "status": "affected",
              "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059",
              "versionType": "git"
            },
            {
              "lessThan": "b8ed41cc04fb74005aa51d17865ca3d022760335",
              "status": "affected",
              "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059",
              "versionType": "git"
            },
            {
              "lessThan": "31a288a4df7f6a28e65da22a4ab2add4a963738e",
              "status": "affected",
              "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059",
              "versionType": "git"
            },
            {
              "lessThan": "64e28ecf44e46de9f01915a4146706a21c3469d2",
              "status": "affected",
              "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059",
              "versionType": "git"
            },
            {
              "lessThan": "994e3e18908f5c4a12d07b44018e6aa85f071048",
              "status": "affected",
              "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059",
              "versionType": "git"
            },
            {
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              "status": "affected",
              "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059",
              "versionType": "git"
            }
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        },
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          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
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            "net/bluetooth/l2cap_sock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "3.5"
            },
            {
              "lessThan": "3.5",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.14.*",
              "status": "unaffected",
              "version": "4.14.308",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "4.19.*",
              "status": "unaffected",
              "version": "4.19.276",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.4.*",
              "status": "unaffected",
              "version": "5.4.235",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.173",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.99",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.16",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.2.*",
              "status": "unaffected",
              "version": "6.2.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.14.308",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "4.19.276",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.4.235",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.10.173",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "5.15.99",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.1.16",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.2.3",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.3",
                  "versionStartIncluding": "3.5",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: L2CAP: Fix potential user-after-free\n\nThis fixes all instances of which requires to allocate a buffer calling\nalloc_skb which may release the chan lock and reacquire later which\nmakes it possible that the chan is disconnected in the meantime."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:A - The vulnerable window is opened and closed by a remote Bluetooth peer over an L2CAP/RFCOMM/LE CoC connection, which requires only radio proximity to the target. Per kernel scoring convention Bluetooth-reachable bugs are Adjacent.\nAC:L - The attacker controls both sides of the race: withholding L2CAP credits (or ACL buffers) parks the sender in the blocking `bt_skb_send_alloc()` with the chan lock released for an unbounded time, and the attacker then terminates the link to run `l2cap_conn_del()`/`kfree(conn)` inside that window. This makes the race deterministic rather than dependent on timing luck.\nPR:N - No local account and no privileges are needed \u2014 the sending side is the kernel\u0027s own RFCOMM session or a system Bluetooth daemon, and L2CAP/LE CoC channels at BT_SECURITY_LOW accept connections without pairing or authentication. The attacker is purely an unauthenticated adjacent device.\nUI:N - Exploitation needs only a connectable/discoverable target or an already-established profile connection; the freed-conn dereference happens entirely within normal send and link-teardown handling. No victim action is required.\nS:U - The corruption and its consequences are confined to the kernel\u0027s own security authority, with no crossing of a VM, IOMMU, or sandbox boundary. This is a standard in-kernel memory-safety issue.\nC:H - This is a use-after-free read of a freed `struct l2cap_conn` slab object whose contents the attacker can influence by reclaiming the slot with heap spray, and the value read (`conn-\u003emtu`) feeds fragment sizing and copy loops. UAF of an attacker-groomable object is treated as enabling arbitrary read.\nI:H - The dangling `l2cap_conn` is used to drive skb allocation and fragmentation while the freed slab is attacker-reclaimable, giving heap-grooming leverage over subsequent kernel allocations and control-flow-relevant state. Per kernel guidance a use-after-free is scored as exploitable for arbitrary write/control-flow hijack.\nA:H - The freed-object read reliably oopses under any hardening (KASAN/slab poisoning) and, when the reclaimed `conn-\u003emtu` reads as 0, `count` becomes 0 so `len` never decreases \u2014 an infinite skb-allocation loop causing hang and memory exhaustion. Either outcome is a full denial of service."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T09:18:06.231Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/b2fde8cb2a25125111f2144604e0e7c0ebcc4bba"
        },
        {
          "url": "https://git.kernel.org/stable/c/a6a7d1541fefddf7ca0cfb34c1bff63ff809cc49"
        },
        {
          "url": "https://git.kernel.org/stable/c/60aaccf16d1e099c16bebfb96428ae762cb528f7"
        },
        {
          "url": "https://git.kernel.org/stable/c/b8ed41cc04fb74005aa51d17865ca3d022760335"
        },
        {
          "url": "https://git.kernel.org/stable/c/31a288a4df7f6a28e65da22a4ab2add4a963738e"
        },
        {
          "url": "https://git.kernel.org/stable/c/64e28ecf44e46de9f01915a4146706a21c3469d2"
        },
        {
          "url": "https://git.kernel.org/stable/c/994e3e18908f5c4a12d07b44018e6aa85f071048"
        },
        {
          "url": "https://git.kernel.org/stable/c/df5703348813235874d851934e957c3723d71644"
        }
      ],
      "title": "Bluetooth: L2CAP: Fix potential user-after-free",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2023-54214",
    "datePublished": "2025-12-30T12:11:11.383Z",
    "dateReserved": "2025-12-30T12:06:44.500Z",
    "dateUpdated": "2026-08-05T09:18:06.231Z",
    "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.

Detection rules are retrieved from Rulezet.

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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