Bluetooth HAS: NULL-pointer dereference DoS when a bonded peer reconnects before bt_has_register
Summary
| CVE | CVE-2026-13213 |
|---|---|
| State | PUBLISHED |
| Assigner | zephyr |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-08-24 18:16:59 UTC |
| Updated | 2026-11-04 05:18:41 UTC |
| Description | The Hearing Access Service (HAS) GATT server in subsys/bluetooth/audio/has.c installs a connection-callback set unconditionally via BT_CONN_CB_DEFINE, so security_changed() runs for every connection that establishes security even before the application has called bt_has_register(). The service attribute pointers hearing_aid_features_attr, preset_control_point_attr, and active_preset_index_attr remain NULL until bt_has_register() resolves them and sets has.registered. With CONFIG_BT_SETTINGS, settings_set_cb() restores each bonded client's persisted context at boot and unconditionally sets context->flags to BONDED_CLIENT_INIT_FLAGS (non-zero). When a previously bonded peer reconnects and re-establishes security during the startup window before bt_has_register() has been called, security_changed() sees the non-zero flags and schedules notify_work_handler, which calls bt_gatt_is_subscribed() with a still-NULL attribute pointer. That triggers an assertion (__ASSERT(attr, ...) in bt_gatt_is_subscribed()), or a NULL dereference of attr->uuid when assertions are compiled out. The result is a remotely triggerable (Bluetooth, adjacent) crash of the HAS peripheral. Exploitation requires the peer to have previously bonded with the device and to reconnect within the boot-time race window before the application registers the service; a peer that reconnects persistently can prolong the outage. Impact is denial of service only, with no memory corruption or information disclosure. The fix adds an early if (!has.registered) { return; } guard in security_changed(), so no notification work is scheduled until the GATT service is registered and its attribute pointers are valid. |
Risk And Classification
Primary CVSS: v3.1 5.3 MEDIUM from [email protected]
CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
EPSS: 0.002460000 probability, percentile 0.160260000 (date 2026-11-04)
Problem Types: CWE-476 | CWE-476 memory-safety
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 3.1 | [email protected] | Secondary | 5.3 | MEDIUM | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 5.3 | MEDIUM | CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v3.1 Breakdown
Attack Vector
AdjacentAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
UnchangedConfidentiality
NoneIntegrity
NoneAvailability
HighCVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Zephyrproject | Zephyr | affected 3.6.0 4.3.2 semver | Not specified |
| CNA | Zephyrproject | Zephyr | affected 4.4.0 4.4.2 semver | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| github.com/zephyrproject-rtos/zephyr/commit/cb2329e090755abde8e57cf1c12a... | [email protected] | github.com | |
| github.com/zephyrproject-rtos/zephyr/security/advisories/GHSA-9rj8-3fvm-... | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.