bt_sdp_parse_attribute() in subsys/bluetooth/host/classic/sdp.c validated only that the SDP record buffer held the type-marker byte plus the 2-byte attribute ID (a check of buf->len < 3) but then read a fourth byte, the data-element descriptor (type), via net_buf_simple_pull_u8(). Because net_buf_simple_pull_u8() dereferences buf->data[0] before its only bounds guard (an __ASSERT_NO_MSG that compiles out when CONFIG_ASSERT is disabled, the production default), a record of exactly three bytes (0x09 followed by a 2-byte attribute ID) causes a one-byte read past the end of the logical buffer. The parser is reachable from inbound, remote-controlled data: a Bluetooth BR/EDR peer acting as an SDP server returns discovery-response records that are stored verbatim in the client receive buffer and parsed via the public bt_sdp_get_attr()/bt_sdp_has_attr()/bt_sdp_record_parse() helpers. The over-read is bounded to a single byte that is used only as an internal length selector and is never leaked to the attacker; subsequent length checks then reject the malformed record. Realistic impact is therefore limited to an edge-case denial of service (a fault only if the record ends exactly at a mapped-memory boundary, or a deterministic assert panic when CONFIG_ASSERT=y). Affects Zephyr v4.3.0 and v4.4.0; fixed by adding sizeof(type) to the length check.
Metrics
Affected Vendors & Products
| Vendors | Products |
|---|---|
| Zephyrproject-rtos |
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No data.
No data.
References
History
Fri, 17 Jul 2026 15:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Weaknesses | CWE-617 |
Tue, 14 Jul 2026 19:00:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A malformed Bluetooth Classic SDP attribute can trigger a reachable assertion in Zephyr's SDP parser. In subsys/bluetooth/host/classic/sdp.c, bt_sdp_parse_attribute() accepts an input buffer once it contains the 1-byte attribute type and 2-byte attribute id, but then unconditionally pulls an additional byte for the value type without verifying that the byte is present. A truncated 3-byte attribute (for example 09 00 09) therefore reaches net_buf_simple_pull() with insufficient remaining length, triggering the __ASSERT_NO_MSG(buf->len >= len) check and a kernel panic in assert-enabled builds (denial of service). In builds where assertions are disabled, parsing may continue past the end of the available buffer, leading to an out-of-bounds read and undefined behavior. | bt_sdp_parse_attribute() in subsys/bluetooth/host/classic/sdp.c validated only that the SDP record buffer held the type-marker byte plus the 2-byte attribute ID (a check of buf->len < 3) but then read a fourth byte, the data-element descriptor (type), via net_buf_simple_pull_u8(). Because net_buf_simple_pull_u8() dereferences buf->data[0] before its only bounds guard (an __ASSERT_NO_MSG that compiles out when CONFIG_ASSERT is disabled, the production default), a record of exactly three bytes (0x09 followed by a 2-byte attribute ID) causes a one-byte read past the end of the logical buffer. The parser is reachable from inbound, remote-controlled data: a Bluetooth BR/EDR peer acting as an SDP server returns discovery-response records that are stored verbatim in the client receive buffer and parsed via the public bt_sdp_get_attr()/bt_sdp_has_attr()/bt_sdp_record_parse() helpers. The over-read is bounded to a single byte that is used only as an internal length selector and is never leaked to the attacker; subsequent length checks then reject the malformed record. Realistic impact is therefore limited to an edge-case denial of service (a fault only if the record ends exactly at a mapped-memory boundary, or a deterministic assert panic when CONFIG_ASSERT=y). Affects Zephyr v4.3.0 and v4.4.0; fixed by adding sizeof(type) to the length check. |
| Title | Bluetooth Classic SDP parser truncation bug in bt_sdp_parse_attribute() leads to reachable assertion and possible out-of-bounds read | Out-of-bounds read in Bluetooth Classic SDP attribute parsing (`bt_sdp_parse_attribute`) |
| Weaknesses | CWE-617 | |
| References |
|
Tue, 23 Jun 2026 13:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Tue, 23 Jun 2026 02:45:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Zephyrproject-rtos
Zephyrproject-rtos zephyr |
|
| Vendors & Products |
Zephyrproject-rtos
Zephyrproject-rtos zephyr |
Tue, 23 Jun 2026 00:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | A malformed Bluetooth Classic SDP attribute can trigger a reachable assertion in Zephyr's SDP parser. In subsys/bluetooth/host/classic/sdp.c, bt_sdp_parse_attribute() accepts an input buffer once it contains the 1-byte attribute type and 2-byte attribute id, but then unconditionally pulls an additional byte for the value type without verifying that the byte is present. A truncated 3-byte attribute (for example 09 00 09) therefore reaches net_buf_simple_pull() with insufficient remaining length, triggering the __ASSERT_NO_MSG(buf->len >= len) check and a kernel panic in assert-enabled builds (denial of service). In builds where assertions are disabled, parsing may continue past the end of the available buffer, leading to an out-of-bounds read and undefined behavior. | |
| Title | Bluetooth Classic SDP parser truncation bug in bt_sdp_parse_attribute() leads to reachable assertion and possible out-of-bounds read | |
| Weaknesses | CWE-20 CWE-617 |
|
| References |
| |
| Metrics |
cvssV3_1
|
MITRE
Status: PUBLISHED
Assigner: zephyr
Published: 2026-06-22T23:54:36.070Z
Updated: 2026-07-17T14:54:49.238Z
Reserved: 2026-06-02T15:24:24.388Z
Link: CVE-2026-10651
Vulnrichment
Updated: 2026-06-23T12:19:40.873Z
NVD
No data.
Redhat
No data.