BHI385 SensorAPI (C Library): Stack-based Buffer Overflow
CVE-2026-42805 is a high-severity stack-based buffer overflow vulnerability in BHI385 SensorAPI (C Library) from Bosch Sensortec, with a CVSS 3.1 base score of 8.4 out of 10. It can be exploited with local access to the system by an unauthenticated attacker, without any action from a user. Affected BHI385 SensorAPI (C Library) versions: 1.1.0 through 2.1.0. The record does not name a fixed version, so check the vendor advisory. There is no confirmed exploitation so far. EPSS estimates a 0.19% chance of exploitation within 30 days, which is low compared with other CVEs.
High severity with no evidence of exploitation so far.
What to do
- Check which version of BHI385 SensorAPI (C Library) you run against the affected versions below, and install the vendor's latest release.
- Read the advisory on psirt.bosch.com for workarounds and exact fixed builds.
Affected products and versions
| Vendor | Product | Affected versions | Fixed in |
|---|---|---|---|
| Bosch Sensortec | BHI385 SensorAPI (C Library) | 1.1.0 through 2.1.0 | Not stated |
Version data comes from the organisation that assigned the CVE. Confirm against the vendor advisory before deciding you are unaffected.
How the severity score breaks down
- Attack vector
- LocalThe attacker needs local access or must trick a user into running something.
- Attack complexity
- LowNo special conditions are needed; the attack works reliably.
- Privileges required
- NoneNo account or login is needed.
- User interaction
- NoneNo action by a victim is required.
- Scope
- UnchangedImpact stays within the vulnerable component.
- Confidentiality
- HighAll data handled by the component can be read.
- Integrity
- HighData or code can be modified at will.
- Availability
- HighThe component can be taken down completely.
Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H. Scored by CNA (bosch.com).
Official description
A stack-based buffer overflow vulnerability exists in the Bosch Sensortec BHI385 SensorAPI (C library) within the debug message parser function bhi385_parse_debug_message (located in bhi385_parse.c). The function parses FIFO events and extracts an 8-bit message length directly from the attacker-controlled event payload (callback_info->data_ptr[0]) without enforcing bounds checks or clamping the value. When copying the payload into a fixed-size stack buffer of 17 bytes (uint8_t debug_msg[17]) via memcpy, providing a length byte greater than 16 causes the function to write past the allocated stack boundary. This memory corruption can be triggered by a malicious or compromised sensor or bus participant, leading to a firmware crash, Denial of Service (DoS), or potentially the execution of arbitrary code via adjacent stack data corruption.
Source: the CVE record as published by its numbering authority, via NVD and CVE.org.
The underlying weakness: Stack-based Buffer Overflow
The product writes past the end of a buffer that was allocated on the stack.
How developers prevent this class of flaw
- Use automatic buffer overflow detection mechanisms that are offered by certain compilers or compiler extensions. Examples include: the Microsoft Visual Studio /GS flag, Fedora/Red Hat FORTIFY_SOURCE GCC flag, StackGuard, and ProPolice, which provide various mechanisms including canary-based detection and range/index checking. D3-SFCV (Stack Frame Canary Validation) from D3FEND discusses canary-based detection in detail.
- Use an abstraction library to abstract away risky APIs. Not a complete solution.
- Implement and perform bounds checking on input.
Timeline
- CVE record published.
- CISA published its SSVC assessment (exploitation: none, automatable: no, technical impact: total).
References
Recent Stack-based Buffer Overflow vulnerabilities
- 7.5 High severity
- 7.0 High severity
- 7.8 High severity
- 7.5 High severity
- 7.5 High severity
- 7.6 High severity
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