CVE-2026-10660— Shared reassembly buffer in Bluetooth BAP Broadcast Assistant enables cross-connection memory corruption

Shared reassembly buffer in Bluetooth BAP Broadcast Assistant enables cross-connection memory corruption

The Bluetooth BAP Broadcast Assistant GATT client in subsys/bluetooth/audio/bap_broadcast_assistant.c reassembled remote Broadcast Receive State data into a single file-static net_buf_simple (att_buf, BT_ATT_MAX_ATTRIBUTE_LEN = 512 bytes) shared by all connection instances, while the BUSY flag, long-read handle, and reset/offset state were per-connection. When the device acts as a Broadcast Assistant connected to multiple Scan Delegator peripherals, notification and long-read callbacks from different connections interleave on the shared buffer: the append in notify_handler (net_buf_simple_add_mem at the not-busy branch) performs no tailroom check, so receive-state notifications from two or more delegators accumulate on the same 512-byte buffer and, with a sufficiently large configured ATT MTU (BT_L2CAP_TX_MTU up to 2000) and two-to-three concurrent connections, write past the buffer into adjacent .bss (net_buf_simple_add only asserts in debug builds). Even below the overflow threshold, one connection's net_buf_simple_reset zeroes the shared length while another connection's reassembly and GATT read offset are in flight, mixing one peer's data into another's parse. A malicious or compromised Scan Delegator (or two colluding peers) over BLE can trigger this, causing out-of-bounds writes (memory corruption / denial of service) and cross-connection data corruption. The fix moves the buffer into the per-connection instance struct so each connection reassembles into its own buffer. Affects Zephyr releases shipping the Broadcast Assistant with the shared buffer, including v4.4.0 and earlier.

CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:H

跨界内存写

Zephyr Project Zephyr 缓冲区错误漏洞

zephyrproject zephyr是zephyrproject组织开源的一款实时操作系统内核。 Zephyr Project Zephyr 3.6.0版本至4.5.0之前版本存在缓冲区错误漏洞，该漏洞源于在subsys/bluetooth/audio/bap_broadcast_assistant.c中，蓝牙BAP广播助手GATT客户端将远程广播接收状态数据重组到一个文件静态的net_buf_simple（att_buf，512字节）缓冲区中，该缓冲区由所有连接实例共享，而BUSY标志、长读取句柄和

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