Threaticon
Toggle sidebar

You're viewing a limited, public preview. Log in for full access.

Log in User Guide
Log in Get started
Vulnerabilities CVE-2026-10682

CVE-2026-10682

Medium
Open
TLP:CLEAR

Out-of-bounds write in Zephyr `log_filter_set` syscall verifier reachable from userspace

AI Analysis

No AI analysis yet.

Description

The userspace verifier z_vrfy_log_filter_set() for the log_filter_set syscall in subsys/logging/log_mgmt.c performed a signed comparison against the int16_t src_id parameter: src_id < (int16_t)log_src_cnt_get(domain_id). Any negative value for src_id (e.g. -1) trivially satisfied this check and was forwarded into z_impl_log_filter_set, where it propagated to filter_set() and ultimately to get_dynamic_filter(), which uses source_id as an unsigned index into the linker-section array &TYPE_SECTION_START(log_dynamic)[source_id].filters. After implicit conversion through uint32_t, an int16_t -1 becomes 0xFFFFFFFF, indexing log_dynamic far out of bounds and causing the kernel to perform an OOB read and an OOB read-modify-write (LOG_FILTER_SLOT_GET/SET) against memory adjacent to the log_dynamic section. The written value is a constrained 3-bit log level slot within the targeted 32-bit word, but the target address is attacker-chosen (a small negative offset from log_dynamic) and the write occurs in supervisor mode following a syscall from an unprivileged user thread, providing a kernel memory-corruption / privilege-escalation primitive. The defect is reachable on any build with CONFIG_USERSPACE=y and CONFIG_LOG_RUNTIME_FILTERING=y. Present from Zephyr v3.3.0 through v4.4.1. The fix replaces the signed bound check with an unsigned comparison: (uint32_t)src_id < log_src_cnt_get(domain_id), which correctly rejects negative inputs.

Details

CVSS Score
6.6
EPSS Score
0.11%

1.8th percentile

CVSS Vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:H
Confidence
90%
Published
Jul 27, 2026
Last Modified
Jul 27, 2026
No notes yet. Click "Add Note" to create the first analysis note.
No opinions yet. Be the first to assess this intelligence.
Leaving Threaticon

This link opens an external site that isn't part of the platform.