{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2023-53673", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-10-07T15:16:59.663Z", "datePublished": "2025-10-07T15:21:29.632Z", "dateUpdated": "2026-08-05T09:15:26.514Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T09:15:26.514Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: hci_event: call disconnect callback before deleting conn\n\nIn hci_cs_disconnect, we do hci_conn_del even if disconnection failed.\n\nISO, L2CAP and SCO connections refer to the hci_conn without\nhci_conn_get, so disconn_cfm must be called so they can clean up their\nconn, otherwise use-after-free occurs.\n\nISO:\n==========================================================\niso_sock_connect:880: sk 00000000eabd6557\niso_connect_cis:356: 70:1a:b8:98:ff:a2 -> 28:3d:c2:4a:7e:da\n...\niso_conn_add:140: hcon 000000001696f1fd conn 00000000b6251073\nhci_dev_put:1487: hci0 orig refcnt 17\n__iso_chan_add:214: conn 00000000b6251073\niso_sock_clear_timer:117: sock 00000000eabd6557 state 3\n...\nhci_rx_work:4085: hci0 Event packet\nhci_event_packet:7601: hci0: event 0x0f\nhci_cmd_status_evt:4346: hci0: opcode 0x0406\nhci_cs_disconnect:2760: hci0: status 0x0c\nhci_sent_cmd_data:3107: hci0 opcode 0x0406\nhci_conn_del:1151: hci0 hcon 000000001696f1fd handle 2560\nhci_conn_unlink:1102: hci0: hcon 000000001696f1fd\nhci_conn_drop:1451: hcon 00000000d8521aaf orig refcnt 2\nhci_chan_list_flush:2780: hcon 000000001696f1fd\nhci_dev_put:1487: hci0 orig refcnt 21\nhci_dev_put:1487: hci0 orig refcnt 20\nhci_req_cmd_complete:3978: opcode 0x0406 status 0x0c\n... ...\niso_sock_sendmsg:1098: sock 00000000dea5e2e0, sk 00000000eabd6557\nBUG: kernel NULL pointer dereference, address: 0000000000000668\nPGD 0 P4D 0\nOops: 0000 [#1] PREEMPT SMP PTI\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014\nRIP: 0010:iso_sock_sendmsg (net/bluetooth/iso.c:1112) bluetooth\n==========================================================\n\nL2CAP:\n==================================================================\nhci_cmd_status_evt:4359: hci0: opcode 0x0406\nhci_cs_disconnect:2760: hci0: status 0x0c\nhci_sent_cmd_data:3085: hci0 opcode 0x0406\nhci_conn_del:1151: hci0 hcon ffff88800c999000 handle 3585\nhci_conn_unlink:1102: hci0: hcon ffff88800c999000\nhci_chan_list_flush:2780: hcon ffff88800c999000\nhci_chan_del:2761: hci0 hcon ffff88800c999000 chan ffff888018ddd280\n...\nBUG: KASAN: slab-use-after-free in hci_send_acl+0x2d/0x540 [bluetooth]\nRead of size 8 at addr ffff888018ddd298 by task bluetoothd/1175\n\nCPU: 0 PID: 1175 Comm: bluetoothd Tainted: G E 6.4.0-rc4+ #2\nHardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-1.fc38 04/01/2014\nCall Trace:\n \n dump_stack_lvl+0x5b/0x90\n print_report+0xcf/0x670\n ? __virt_addr_valid+0xf8/0x180\n ? hci_send_acl+0x2d/0x540 [bluetooth]\n kasan_report+0xa8/0xe0\n ? hci_send_acl+0x2d/0x540 [bluetooth]\n hci_send_acl+0x2d/0x540 [bluetooth]\n ? __pfx___lock_acquire+0x10/0x10\n l2cap_chan_send+0x1fd/0x1300 [bluetooth]\n ? l2cap_sock_sendmsg+0xf2/0x170 [bluetooth]\n ? __pfx_l2cap_chan_send+0x10/0x10 [bluetooth]\n ? lock_release+0x1d5/0x3c0\n ? mark_held_locks+0x1a/0x90\n l2cap_sock_sendmsg+0x100/0x170 [bluetooth]\n sock_write_iter+0x275/0x280\n ? __pfx_sock_write_iter+0x10/0x10\n ? __pfx___lock_acquire+0x10/0x10\n do_iter_readv_writev+0x176/0x220\n ? __pfx_do_iter_readv_writev+0x10/0x10\n ? find_held_lock+0x83/0xa0\n ? selinux_file_permission+0x13e/0x210\n do_iter_write+0xda/0x340\n vfs_writev+0x1b4/0x400\n ? __pfx_vfs_writev+0x10/0x10\n ? __seccomp_filter+0x112/0x750\n ? populate_seccomp_data+0x182/0x220\n ? __fget_light+0xdf/0x100\n ? do_writev+0x19d/0x210\n do_writev+0x19d/0x210\n ? __pfx_do_writev+0x10/0x10\n ? mark_held_locks+0x1a/0x90\n do_syscall_64+0x60/0x90\n ? lockdep_hardirqs_on_prepare+0x149/0x210\n ? do_syscall_64+0x6c/0x90\n ? lockdep_hardirqs_on_prepare+0x149/0x210\n entry_SYSCALL_64_after_hwframe+0x72/0xdc\nRIP: 0033:0x7ff45cb23e64\nCode: 15 d1 1f 0d 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b8 0f 1f 00 f3 0f 1e fa 80 3d 9d a7 0d 00 00 74 13 b8 14 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 54 c3 0f 1f 00 48 83 ec 28 89 54 24 1c 48 89\nRSP: 002b:00007fff21ae09b8 EFLAGS: 00000202 ORIG_RAX: 0000000000000014\nRAX: ffffffffffffffda RBX: \n---truncated---" } ], "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 bug is in the Bluetooth HCI event handler, triggered by a Command Status event for HCI_Disconnect whose failure status is induced by a peer device terminating the link concurrently with the host's disconnect. Exploitation requires only Bluetooth radio proximity to the target (phones, cars, headsets, laptops), which is CVSS Adjacent.\nAC:L - The attacker controls both sides of the race: closing the last L2CAP channel forces hcon->disc_timeout=0 and an immediate host Disconnect, and the attacker then tears down the link-layer connection at that moment so the controller answers Unknown Connection Identifier/Command Disallowed. The attempt costs nothing and can be repeated indefinitely by reconnecting.\nPR:N - No credentials or pairing are required — an L2CAP/ISO connection reaches l2cap_conn_add/iso_conn_add before authentication, and no capability check exists on the path. The attacker needs no account or privilege on the target system.\nUI:N - The dangling l2cap_conn->hchan and iso_conn->hcon are used by ordinary background traffic — the reported crash occurred in bluetoothd's normal write path — with no victim action needed. The attacker can also trigger the use itself via further protocol activity.\nS:U - The freed objects and the resulting corruption are entirely within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed hci_chan lives in the generic kmalloc-64 cache and hci_send_acl dereferences chan->conn->hdev straight out of it, so a groomed reallocation yields a controlled pointer read of arbitrary kernel memory. Per kernel guidance, use-after-free is scored High confidentiality.\nI:H - Beyond the read primitive, hci_queue_acl writes skb list pointers into the freed object's data_q and later code operates on the forged hci_conn, giving heap-spray-driven write and control-flow influence. Use-after-free of a sprayable kmalloc object is scored High integrity.\nA:H - The bug reproduces as a KASAN slab-use-after-free in hci_send_acl and as a NULL pointer dereference oops in iso_sock_sendmsg, both fatal to the kernel context. Any kernel oops/panic is High availability." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/bluetooth/hci_event.c" ], "versions": [ { "version": "b8d290525e3972b5e876b2649a42bf4081d753fe", "lessThan": "1ecf6dc2676ead4b927c50b1be0851fa4d756574", "status": "affected", "versionType": "git" }, { "version": "b8d290525e3972b5e876b2649a42bf4081d753fe", "lessThan": "59bd1e476bbc7bc6dff3c61bba787095a4839796", "status": "affected", "versionType": "git" }, { "version": "b8d290525e3972b5e876b2649a42bf4081d753fe", "lessThan": "093a07052406b363b1b2ab489e17dbadaf3e509b", "status": "affected", "versionType": "git" }, { "version": "b8d290525e3972b5e876b2649a42bf4081d753fe", "lessThan": "7f7cfcb6f0825652973b780f248603e23f16ee90", "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/hci_event.c" ], "versions": [ { "version": "5.7", "status": "affected" }, { "version": "0", "lessThan": "5.7", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.200", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.42", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.4.7", "lessThanOrEqual": "6.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.5", "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": "5.7", "versionEndExcluding": "5.15.200" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.1.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.4.7" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.7", "versionEndExcluding": "6.5" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/1ecf6dc2676ead4b927c50b1be0851fa4d756574" }, { "url": "https://git.kernel.org/stable/c/59bd1e476bbc7bc6dff3c61bba787095a4839796" }, { "url": "https://git.kernel.org/stable/c/093a07052406b363b1b2ab489e17dbadaf3e509b" }, { "url": "https://git.kernel.org/stable/c/7f7cfcb6f0825652973b780f248603e23f16ee90" } ], "title": "Bluetooth: hci_event: call disconnect callback before deleting conn", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "metrics": [ { "other": { "type": "ssvc", "content": { "id": "CVE-2023-53673", "role": "CISA Coordinator", "options": [ { "Exploitation": "none" }, { "Automatable": "no" }, { "Technical Impact": "total" } ], "version": "2.0.3", "timestamp": "2026-06-10T20:41:12.221027Z" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-06-11T18:44:09.846Z" } } ] } }