solution Contentsolution Content

HP t430 and t638 Thin Clients - Firmware Tampering Vulnerability

HP is aware of a potential security vulnerability in HP t430 and t638 Thin Client PCs. These models may be susceptible to a physical attack, allowing an untrusted source to tamper with the system firmware using a publicly disclosed private key. HP is providing recommended guidance for customers to reduce exposure to the potential vulnerability.



HP Reference

HPSBHF03873 Rev. 1

Release date

October 13, 2023

Last updated

October 13, 2023



Potential Security Impact

Escalation of Privilege, Arbitrary Code Execution, and Denial of Service


For HP t430 and t638 Thin Clients PCs manufactured before July 2023, a private firmware key has been disclosed, potentially allowing an untrusted source to tamper with system firmware. HP has not identified any active exploits related to this vulnerability, which requires physical access to the system.

HP t430 and t638 Thin Client BIOS images are signed with undisclosed HP-unique keys protected by a Hardware Security Module. This BIOS image key provides additional protections that maintain integrity for BIOS updates and normal system usage.

Relevant Common Vulnerabilities and Exposures (CVE) List

Reported by Binarly REsearch Team

List of CVE IDs


CVS 3.0





Learn more about CVSS 3.0 base metrics, which range from 0 to 10.



HP recommends that customers implement these recommendations to mitigate their exposure to the identified vulnerability.

  • Limit Physical Access to Devices: Customers should limit physical access to their devices as a precautionary measure.

  • Update BIOS Using Firmware from HP: Customers should only update devices with firmware provided directly from HP or its website.

  • Enable BIOS Admin/Setup Password: As a standard practice, HP recommends that all customers create a primary Admin account and password for each affected device. This will help protect against unintended access to the BIOS.

  • Disable USB Ports During Boot Process: Customers should disable the USB Storage Boot BIOS setting to prevent unauthorized users from booting to and installing malicious software. This can be disabled manually in the BIOS startup menu; via running a script in HP Device Manager or another endpoint management software; or via custom BIOS firmware updates.

Newer versions may become available, and the minimum versions listed below may become obsolete.  If a SoftPaq Link becomes invalid, check the HP Customer Support - Software and Driver Downloads site to obtain the latest update for your product model.

HP recommends keeping your system up to date with the latest firmware and software.


This bulletin may be updated when new information and/or SoftPaqs are available. Sign up for HP Subscriptions to be notified and receive:

  • Product support eAlerts

  • Driver updates

  • Security Bulletin updates

Affected products

Identify the affected products.

Thin Client PCs

Product Name

Component Type

Minimum Version

SoftPaq #

SoftPaq Link

HP t430 Thin Client







HP t638 Thin Client




Revision history

This document has been revised according to the information below.

List of versions





Initial Release

October 13, 2023

Additional information

Follow these links for additional information.

Third-party security patches

Third party security patches that are to be installed on systems running HP software products should be applied in accordance with the customer's patch management policy.


For issues about implementing the recommendations of this Security Bulletin, visit to learn about your HP support options.


To report a potential security vulnerability with any HP supported product, send email to:


To initiate a subscription to receive future HP Security Bulletin alerts via email, visit

Security bulletin archive

To view released Security Bulletins, visit

It is strongly recommended that security related information being communicated to HP be encrypted using PGP, especially exploit information.

Download HP’s security-alert PGP key

Legal information

System management and security procedures must be reviewed frequently to maintain system integrity. HP is continually reviewing and enhancing the security features of software products to provide customers with current secure solutions.

HP is broadly distributing this Security Bulletin in order to bring to the attention of users of the affected HP products the important security information contained in this Security Bulletin. HP recommends that all users determine the applicability of this information to their individual situations and take appropriate action. HP does not warrant that this information is necessarily accurate or complete for all user situations and, consequently, HP will not be responsible for any damages resulting from user's use or disregard of the information provided in this Security Bulletin. To the extent permitted by law, HP disclaims all warranties, either express or implied, including the warranties of merchantability and fitness for a particular purpose, title and non-infringement.

© Copyright 2023 HP Development Company, L.P.

HP Inc. (HP) shall not be liable for technical or editorial errors or omissions contained herein. The information provided is provided "as is" without warranty of any kind. To the extent permitted by law, neither HP nor its affiliates, subcontractors or suppliers will be liable for incidental, special or consequential damages including downtime cost; lost profits; damages relating to the procurement of substitute products or services; or damages for loss of data, or software restoration. The information in this document is subject to change without notice. "HP Inc.," "HP" and the names of HP products referenced herein are trademarks of HP Inc. or its affiliates in the United States and other countries. Other product and company names mentioned herein may be trademarks of their respective owners.