GHSA-p93g-3r68-cj53: Out-of-bounds read in Bluetooth Classic SDP attribute parsing (`bt_sdp_parse_attribute`)

Published Jun 22, 2026
·
Updated

btsdpparseattribute() 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 netbufsimplepullu8(). Because netbufsimplepullu8() dereferences buf->data[0] before its only bounds guard (an ASSERTNOMSG that compiles out when CONFIGASSERT 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 btsdpgetattr()/btsdphasattr()/btsdprecordparse() 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 CONFIGASSERT=y). Affects Zephyr v4.3.0 and v4.4.0; fixed by adding sizeof(type) to the length check.

Affected Software

1 affected component
Zephyr Zephyr=4.3.0, =4.4.0

Remediation

Recommended actions to resolve this vulnerability, in priority order.

  1. Compensating control

    Update bt_sdp_parse_attribute() in Zephyr's Bluetooth Classic SDP parser to add sizeof(type) to the length check, ensuring the buffer contains the data-element descriptor byte before net_buf_simple_pull_u8() reads it.

Event History

Jun 22, 2026
CVE Published
via OSV·11:54 PM
Data Sourced
via OSV·11:54 PM
DescriptionSeverityWeakness

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