{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-54214", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-12-30T12:06:44.500Z", "datePublished": "2025-12-30T12:11:11.383Z", "dateUpdated": "2026-08-05T09:18:06.231Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:18:06.231Z" }, "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": { "version": "3.1", "vectorString": "CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "baseScore": 8.8, "baseSeverity": "HIGH" }, "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 — the sending side is the kernel's 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's 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->mtu`) 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->mtu` reads as 0, `count` becomes 0 so `len` never decreases — an infinite skb-allocation loop causing hang and memory exhaustion. Either outcome is a full denial of service." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/l2cap_core.c", "net/bluetooth/l2cap_sock.c" ], "versions": [ { "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059", "lessThan": "b2fde8cb2a25125111f2144604e0e7c0ebcc4bba", "status": "affected", "versionType": "git" }, { "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059", "lessThan": "a6a7d1541fefddf7ca0cfb34c1bff63ff809cc49", "status": "affected", "versionType": "git" }, { "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059", "lessThan": "60aaccf16d1e099c16bebfb96428ae762cb528f7", "status": "affected", "versionType": "git" }, { "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059", "lessThan": "b8ed41cc04fb74005aa51d17865ca3d022760335", "status": "affected", "versionType": "git" }, { "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059", "lessThan": "31a288a4df7f6a28e65da22a4ab2add4a963738e", "status": "affected", "versionType": "git" }, { "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059", "lessThan": "64e28ecf44e46de9f01915a4146706a21c3469d2", "status": "affected", "versionType": "git" }, { "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059", "lessThan": "994e3e18908f5c4a12d07b44018e6aa85f071048", "status": "affected", "versionType": "git" }, { "version": "a6a5568c03c4805d4d250f6bd9d468eeeb4ea059", "lessThan": "df5703348813235874d851934e957c3723d71644", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/l2cap_core.c", "net/bluetooth/l2cap_sock.c" ], "versions": [ { "version": "3.5", "status": "affected" }, { "version": "0", "lessThan": "3.5", "status": "unaffected", "versionType": "semver" }, { "version": "4.14.308", "lessThanOrEqual": "4.14.*", "status": "unaffected", "versionType": "semver" }, { "version": "4.19.276", "lessThanOrEqual": "4.19.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.235", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.173", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.99", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.16", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.2.3", "lessThanOrEqual": "6.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "4.14.308" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "4.19.276" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "5.4.235" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "5.10.173" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "5.15.99" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.1.16" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.2.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.5", "versionEndExcluding": "6.3" } ] } ] } ], "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" } } } }