The STM32WBA IEEE 802.15.4 driver in drivers/ieee802154/ieee802154_stm32wba.c computed the packet length of a received frame as pkt_len = rx_frame->length - IEEE802154_FCS_LENGTH without first checking that the radio-reported length could hold an FCS. pkt_len is a uint8_t, so a reported length of 0 or 1 wrapped to 254 or 255. The only bound on the resulting value was __ASSERT_NO_MSG(pkt_len <= CONFIG_NET_BUF_DATA_SIZE), which compiles to nothing in the default production configuration (CONFIG_ASSERT=n). The length originates in the ST link-layer receive-done metadata (p_metadata->length, stored by stm32wba_802154_receive_done()), and ultimately in the PHY header of a frame received over the air, so it is influenced by any attacker within radio range of the device. Reaching the underflow requires the vendor link layer to surface a frame shorter than the FCS with no error; the driver performed no validation of its own on that value. When the underflow occurs, stm32wba_802154_rx_thread() calls net_pkt_write(pkt, rx_frame->psdu, pkt_len) with a length of about 254 bytes against a receive buffer that holds at most one PHY packet (IEEE802154_MAX_PHY_PACKET_SIZE, 127 bytes). This reads roughly 128 bytes past the end of the radio receive buffer and copies that adjacent memory into a network packet that is submitted to the networking stack, giving an out-of-bounds read with a potential disclosure of adjacent RAM plus needless oversized packet allocation in the RX thread. The fix rejects a frame whose reported length is smaller than IEEE802154_FCS_LENGTH before the subtraction, and replaces the compiled-out assertion with a runtime length check that drops oversized frames — matching the runtime check already present in drivers/ieee802154/ieee802154_nrf5.c.
| Métrique | Valeur | Interprétation |
|---|---|---|
|
AV (Vecteur d'Attaque)
Attack Vector
|
Adjacent (A)
|
Exploit nécessite un accès au segment réseau local |
|
AC (Complexité d'Attaque)
Attack Complexity
|
High (H)
|
Conditions spécifiques doivent être réunies pour exploiter |
|
PR (Privilèges Requis)
Privileges Required
|
None (N)
|
Aucune authentification requise |
|
UI (Interaction Utilisateur)
User Interaction
|
None (N)
|
Aucune interaction utilisateur nécessaire |
|
S (Périmètre)
Scope
|
Unchanged (U)
|
Impact reste dans le périmètre du composant compromis |
|
C (Impact Confidentialité)
Confidentiality Impact
|
Low (L)
|
Divulgation limitée d'informations |
|
I (Impact Intégrité)
Integrity Impact
|
None (N)
|
Aucune modification de données possible |
|
A (Impact Disponibilité)
Availability Impact
|
Low (L)
|
Interruption partielle du service possible |
Out-of-bounds read from received-frame length underflow in the STM32WBA IEEE 802.15.4 driver