CVE-2026-43023
In the Linux kernel, the following vulnerability has been resolved:
Bluetooth: SCO: fix race conditions in sco_sock_connect()
sco_sock_connect() checks sk_state and sk_type without holding the socket lock. Two concurrent connect() syscalls on the same socket can both pass the check and enter sco_connect(), leading to use-after-free.
The buggy scenario involves three participants and was confirmed with additional logging instrumentation:
Thread B revives a BT_CLOSED + SOCK_ZAPPED socket back to BT_CONNECT. Subsequent cleanup triggers double sock_put() and use-after-free. Meanwhile conn1 is leaked as it was orphaned when sco_conn_del() cleared the association.
Leer descripción completaMostrar menos
Fix this by: - Moving lock_sock() before the sk_state/sk_type checks in sco_sock_connect() to serialize concurrent connect attempts - Fixing the sk_type != SOCK_SEQPACKET check to actually return the error instead of just assigning it - Adding a state re-check in sco_connect() after lock_sock() to catch state changes during the window between the locks - Adding sco_pi(sk)->conn check in sco_chan_add() to prevent double-attach of a socket to multiple connections - Adding hci_conn_drop() on sco_chan_add failure to prevent HCI connection leaks
Detalles técnicos trazas, registros y código del informe original
Thread A (connect): HCI disconnect: Thread B (connect):
sco_sock_connect(sk) sco_sock_connect(sk)
sk_state==BT_OPEN sk_state==BT_OPEN
(pass, no lock) (pass, no lock)
sco_connect(sk): sco_connect(sk):
hci_dev_lock hci_dev_lock
hci_connect_sco <- blocked
-> hcon1
sco_conn_add->conn1
lock_sock(sk)
sco_chan_add:
conn1->sk = sk
sk->conn = conn1
sk_state=BT_CONNECT
release_sock
hci_dev_unlock
hci_dev_lock
sco_conn_del:
lock_sock(sk)
sco_chan_del:
sk->conn=NULL
conn1->sk=NULL
sk_state=
BT_CLOSED
SOCK_ZAPPED
release_sock
hci_dev_unlock
(unblocked)
hci_connect_sco
-> hcon2
sco_conn_add
-> conn2
lock_sock(sk)
sco_chan_add:
sk->conn=conn2
sk_state=
BT_CONNECT
// zombie sk!
release_sock
hci_dev_unlockCVSS
- Versión: 3.1
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- Puntuación base: 7.8
Probabilidad de explotación (EPSS)
- Probabilidad de explotación en los próximos 30 días: 0.13%
- Percentil entre todas las CVEs puntuadas: 2
- Fecha de la puntuación: 6/10/2026
EPSS (Exploit Prediction Scoring System, de FIRST) estima la probabilidad de que una vulnerabilidad sea explotada en 30 días. Complementa a CVSS (impacto) y a CISA KEV (explotación confirmada).
🎯 Técnicas ATT&CK
Cómo se explota esta vulnerabilidad y qué consigue el atacante, en el lenguaje de MITRE ATT&CK.
- Explotación
T1068Exploitation for Privilege Escalationprivilege escalation85 % - Impacto secundario
T1499.004Application or System Exploitationimpact70 %
Acceso local sin interacción de usuario (AV:L/UI:N/PR:L) permite escalada de privilegios mediante race condition en Bluetooth SCO que causa use-after-free y DoS.
Inferido por nuestro agente de análisis a partir de la descripción oficial, el vector CVSS y la CWE, y comprobado por un supervisor. Puede contener errores.
🛡️ Mitigaciones ATT&CK que cubren estas técnicas
Tecnologías afectadas (1)
CWE
- CWE-362
Referencias
- https://git.kernel.org/stable/c/7e296ffdab5bdab718dff7c14288fdcb9154fa27
- https://git.kernel.org/stable/c/8a5b0135d4a5d9683203a3d9a12a711ccec5936b
- https://git.kernel.org/stable/c/98c8d3bfdaa657d8f472dbbebd7ea8cd816d8a8d
- https://git.kernel.org/stable/c/adb90cd0f9f7a8d438fcb93354040fbafc5ae2a0
- https://git.kernel.org/stable/c/d002bd11024bd231bcb606877e33951ffb7bed14
- https://git.kernel.org/stable/c/dabf22269242e2f2bf44c43fcdc2fa763df7f9cc
JSON original (NVD)
Mostrar
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"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nBluetooth: SCO: fix race conditions in sco_sock_connect()\n\nsco_sock_connect() checks sk_state and sk_type without holding\nthe socket lock. Two concurrent connect() syscalls on the same\nsocket can both pass the check and enter sco_connect(), leading\nto use-after-free.\n\nThe buggy scenario involves three participants and was confirmed\nwith additional logging instrumentation:\n\n Thread A (connect): HCI disconnect: Thread B (connect):\n\n sco_sock_connect(sk) sco_sock_connect(sk)\n sk_state==BT_OPEN sk_state==BT_OPEN\n (pass, no lock) (pass, no lock)\n sco_connect(sk): sco_connect(sk):\n hci_dev_lock hci_dev_lock\n hci_connect_sco <- blocked\n -> hcon1\n sco_conn_add->conn1\n lock_sock(sk)\n sco_chan_add:\n conn1->sk = sk\n sk->conn = conn1\n sk_state=BT_CONNECT\n release_sock\n hci_dev_unlock\n hci_dev_lock\n sco_conn_del:\n lock_sock(sk)\n sco_chan_del:\n sk->conn=NULL\n conn1->sk=NULL\n sk_state=\n BT_CLOSED\n SOCK_ZAPPED\n release_sock\n hci_dev_unlock\n (unblocked)\n hci_connect_sco\n -> hcon2\n sco_conn_add\n -> conn2\n lock_sock(sk)\n sco_chan_add:\n sk->conn=conn2\n sk_state=\n BT_CONNECT\n // zombie sk!\n release_sock\n hci_dev_unlock\n\nThread B revives a BT_CLOSED + SOCK_ZAPPED socket back to\nBT_CONNECT. Subsequent cleanup triggers double sock_put() and\nuse-after-free. Meanwhile conn1 is leaked as it was orphaned\nwhen sco_conn_del() cleared the association.\n\nFix this by:\n- Moving lock_sock() before the sk_state/sk_type checks in\n sco_sock_connect() to serialize concurrent connect attempts\n- Fixing the sk_type != SOCK_SEQPACKET check to actually\n return the error instead of just assigning it\n- Adding a state re-check in sco_connect() after lock_sock()\n to catch state changes during the window between the locks\n- Adding sco_pi(sk)->conn check in sco_chan_add() to prevent\n double-attach of a socket to multiple connections\n- Adding hci_conn_drop() on sco_chan_add failure to prevent\n HCI connection leaks"
}
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"lastModified": "2026-06-17T10:48:47.027",
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