Zephyr Bluetooth Host vulnerabilities

A vulnerability in the Zephyr Bluetooth host stack causes a double-free of a net_buf in the ATT transmit path when signing fails. Additionally, on a bt_l2cap_send_pdu() failure, a buffer may be reused with a stale signature, leading to an out-of-bounds write. This results in memory corruption, crashes, or potential code execution.

A vulnerability in the parse_read_std_char_desc() function in the Bluetooth host subsystem (subsys/bluetooth/host/gatt.c) allows a remote, unauthenticated device to hang the Bluetooth processing thread by sending an ATT response with a zero entry length (rsp->len = 0). The parsing loop does not validate the minimum value of rsp->len, leading to an infinite loop (CWE-835) and failure to terminate descriptor discovery.

In the Bluetooth host stack, during L2CAP LE CoC SDU reassembly, a remote unauthenticated BLE peer can trigger a 2-byte out-of-bounds write. This occurs when segmentation is enabled and the chosen RX pool has user_data_size smaller than 2 bytes, causing the segmentation counter to be written out of bounds in l2cap_chan_le_recv_seg.