Category Archives: IoT

Android Security Bulletin – May 2024 There’s a lot you can explore (9 May 2024)

Preface: Heard that Long-term support (LTS) for Linux kernels is being reduced from six to two years now.

Background: Greg Kroah-Hartman is a major Linux kernel developer. As of April 2013, he is the Linux kernel maintainer for the -stable branch, the staging subsystem, USB, driver core, debugfs, kref, kobject, and the sysfs kernel subsystems, Userspace I/O, and TTY layer.

What will be the next LTS kernel?

But in any event Greg Kroah-Hartman has decided to go ahead and declare Linux 6.6 as the newest LTS kernel. has been updated to reflect Linux 6.6 LTS. The current plan is for Linux 6.6 to be maintained until going end-of-life in December 2026: the same time Linux 6.1, 5.15, and 5.10 will reach end-of-life.

Android Security Bulletin—May 2024 (Published May 6, 2024)

The diagram above shows that kernel versions have been updated. Kernel version updates are dependent on the version of Android OS at the time of device launch. Please refer to the following link for details:

CVE-2024-4017 and CVE-2024-4018 on BeyondTrust (19-04-2024)

Preface: CyberArk most likely to be known as a leader in PAM. BeyondTrust more popular among small and medium-sized enterprises.

Background: U-Series is a self-contained physical or virtual appliance that contains the operating system, the database, the BeyondTrust BeyondInsight platform, and the BeyondTrust Password Safe solution.

For a BeyondInsight deployment with a local SQL Server instance, the minimum requirement is 32GB. It is based on Microsoft Windows Server 2022 Standard operating system. The license included with the U-Series v20 and U-Series v20 SQL Free for Microsoft Windows Server 2022 covers up to 16 cores on the physical virtualization (host) server.

Vulnerability details:

CVE-2024-4018: Improper Privilege Management vulnerability in BeyondTrust U-Series Appliance on Windows, 64 bit (local appliance api modules) allows Privilege Escalation.This issue affects U-Series Appliance: from 3.4 before 4.0.3. Please refer to the link for details –

CVE-2024-4017: Improper Privilege Management vulnerability in BeyondTrust U-Series Appliance on Windows, 64 bit (filesystem modules) allows DLL Side-Loading.This issue affects U-Series Appliance: from 3.4 before 4.0.3. Please refer to the link for details –

CVE-2024-1633: Do not contempt! (19th Feb 2024)

Preface: A two-stage bootloader actually consists of two bootloaders after each other. The first being small with the sole purpose of loading the second one. The second one can then contain all the code needed for loading the kernel.

Background: Secure boot is a security standard developed to help make sure that a device boots using only software that is trusted by the Original Equipment Manufacturer (OEM). When the device starts, the firmware checks the signature of each piece of boot software. If the signatures are valid, the device boots, and the firmware gives control to the operating system.

Vulnerability details: During the secure boot, bl2 (the second stage of the bootloader) loops over images defined in the table “bl2_mem_params_descs”. For each image, the bl2 reads the image length and destination from the image’s certificate. Because of the way of reading from the image, which base on 32-bit unsigned integer value, it can result to an integer overflow. An attacker can bypass memory range restriction and write data out of buffer bounds, which could result in bypass of secure boot.


An integer overflow occurs when you attempt to store inside an integer variable a value that is larger than the maximum value the variable can hold.

A 32-bit unsigned integer. It has a minimum value of 0 and a maximum value of 4,294,967,295 (inclusive).

Official details: Please refer to the link for details –

About CVE-2023-3220 An issue was discovered in the Linux kernel through 6.1-rc8 (20th June 2023)

Preface: AI Engines are built from the ground up to be software programmable and hardware adaptable. There are two distinct design flows for any developer to unleash the performance of these compute engines with the ability to compile in minutes and rapidly explore different microarchitectures.
As of today, current technology are capable On-device intelligence powered by the AI Engine. Our dreams come true, the 3rd generation AI Engine enables on-device intelligence and simplifies how pictures and videos are taken.

Background: The Qualcomm Robotics RB3 development kit includes the purpose-built robotics-focused DragonBoard™ 845c development board, based on the Qualcomm® SDA845 processor and compliant with the 96Boards open hardware specification to support a broad range of mezzanine-board expansions.
The development board supports Linux and Robotics Operating System (ROS), while also including support for the Qualcomm® Neural Processing software development kit (SDK) for advanced on-device AI, the Qualcomm ® Computer Vision Suite, the Qualcomm ® Hexagon DSP SDK, and AWS RoboMaker.

Vulnerability details: An issue was discovered in the Linux kernel through 6.1-rc8. dpu_crtc_atomic_check in drivers/gpu/drm/msm/disp/dpu1/dpu_crtc[.]c lacks check of the return value of kzalloc() and will cause the NULL Pointer Dereference.

Ref: The kzalloc() function is the same as kmalloc().
Difference: Cleared to zero after memory allocation is successful. After each use of kzalloc(), there must be a corresponding memory release function kfree().

Official announcement: For details, please refer to the link –

CVE-2023-34868 – JerryScript Design weakness (15th June 2023)

Preface: Samsung said that Open Source is not only the development method also a culture and various things. Samsung always keep in mind to give back to Open Source through their activities. They are partake in the culture of sharing and collaboration with the list of projects they have released and contributed to.

Background: The IoT.js platform uses JerryScript to run JavaScript code and libuv for asynchronous I/O, and enables developers to create IoT services that communicate with each other and the outside world.
JerryScript is a very lightweight JavaScript engine with capability to run on microcontrollers with less than 8KB of RAM.

Vulnerability details:
CVE-2023-34868 – Jerryscript 3.0 (commit 05dbbd1) was discovered to contain an Assertion Failure via the parser_parse_for_statement_start at jerry-core[/]parser[/]js[/]js-parser-statm[.]c.
My Predcit Consequence: The possibility of triggering an assertion failure, which could cause the BIND process to terminate.

In addition there is another one.
CVE-2023-34867 – Jerryscript 3.0 (commit 05dbbd1) was discovered to contain an Assertion Failure via the ecma_property_hashmap_create at jerry-core[/]ecma[/]base[/]ecma-property-hashmap[.]c.

About Qualcomm: The vulnerability of CVE-2022-40507 release to public on 06/06/2023 finally.

Preface: Double free errors occur when free() is called more than once with the same memory address as an argument. Calling free() twice on the same value can lead to memory leak. When a program calls free() twice with the same argument, the program’s memory management data structures become corrupted and could allow a malicious user to write values in arbitrary memory spaces.

Background: SnapDragon has different processors runn on top of SOC (see below):
Krait CPU — General purpose processor that usually runs android applications.
Adreno GPU — This is largely used for graphics processing like rendering.
Hexagon DSP — Hexagon specially designed for multi-media acceleration, this helps CPU to offload the task to DSP and save energy and thereby offering optimum performance.

Vulnerability details: Memory corruption due to double free in Core while mapping HLOS address to the list.

The vulnerability release to public on 06/06/2023. The announcement can be read at –
This vulnerability has been identified as CVE-2022-40507 since 09/12/2022. The vendor did not release technical details.

How to observe memory allocation in Linux kernel?
Generate the skeleton for the task named 1-mem and browse the contents of the mem[.]c file. Observe the use of kmalloc() call for memory allocation.

  1. Compile the source code and load the mem[.]ko module using insmod.
  2. View the kernel messages using the dmesg command.
  3. Unload the kernel module using the rmmod mem command.

Cyber Défense from narrow to broad  (5th Jan 2023)

Preface: Sustainability is a buzzword in the modern world in recent years. It applies to business, culture…even our education. A slogan, keep learning. Maybe it’s the Cantonese mantra, One is never too old to learn. Perhaps it also apply to cyber security protection.

Background: In last twenty years, computing technology driven growth of the world. The rapid growth of telecommunication especially TCP/IP communication protocol. The invention of this technology unintended interconnect different zone and culture. The TCP/IP network protocol  empower to Industrial world transformation. So we have industrial 4.0, smart city facilities and smart home. This is the theory of sustainability. But this key word just appear in last five years.

We all concerning privacy. So European countries and union driven GDPR. Whatever data run in internet including your personal data, web browser connection cookies are fall into their protection coverage. Before that, cyber security vendor especially antivirus and cyber security protection vendor have been done predictive technology. Their way is do a passive information gathering. When incident occur with unknown cyber-attack, they will do enhancement based on your former activities log.

Cyber defence from narrow to broad  : Set up monitoring and logging of systems that trip the DNS sinkhole so that they can be investigated and remediated if they are infected with malware. Until now, such services have been run by private business owners. So if you can afford to pay for the service, you can receive updates from the online world. To avoid risking your connection, such service will integrate to your defence solution can provide protection. Perhaps this is a narrow usage.

We all know that artificial intelligence improves our lives. But they rely on data. In fact, enterprise companies, especially Amazon, Google, Cisco… are already using AI technologies in their cyber defence solutions. So their umbrella technology covers a lot. Whether it is prevention, detection or correction, it is in place. However, they are all running businesses and thus have not disclosed their technology to the public.

But when will generalized artificial intelligence develop. For example, this month the cybersecurity defence vendor discovered malicious activity that can infect the operating system Linux. In fact, AI can target these activities and make predictions (see attached image).

Sustainability seems to be the definition of the big data world. The accumulation of data to the database is a long-term process. So keywords accumulate or sustainably contain similarities.

For more information about cyber-attacks against Linux environments, you can find the details at the link –

If your IoT development is based on Zigbee,perhaps Zephyr CVE will bring to your consideration. (6th Oct 2021)

Preface: Ensure that the JSON parser does not try to write a potentially unlimited number of elements into a C array of a fixed size.

Background: Zephyr is a small real-time operating system (RTOS) for connected, resource-constrained and embedded devices (with an emphasis on microcontrollers) supporting multiple architectures and released under the Apache License 2.0. Zephyr includes a kernel, and all components and libraries, device drivers, protocol stacks, file systems, and firmware updates, needed to develop full application software. Furthermore the footprint as small as 8K.

Vulnerability details: Till now, the CVSS score not been defined yet. According to 4 different vulnerabilities registered this month. There are two different vulnerabilities related to BLE. Besides, a vulnerability related to Zigbee. The remaining one is related to JSON decoder. The flaw of JSON decoder display as below: When using JSON_OBJ_DESCR_ARRAY_ARRAY, the subarray is has the token type JSON_TOK_LIST_START, but then assigns to the object part of the union. “arr_parse” then takes the offset of the array-object (which has nothing todo with the list) treats it as relative to the parent object, and stores the length of the subarray in there. For the details of this vulnerability, please refer to link –

The following list shows other CVE details:


CVE-2021-3436 –

CVE-2021-3581 –


CVE-2021-3319 –

32-bit design limitation (0x7ffffffff). Another episode of Y2K. (23-07-2021)

Preface: Because humans have destroyed the environment. Therefore, natural disasters resemble God’s punishment. In the digital world, the situation is the same. The reason for the penalty is the design weakness of the software.

Background: Perhaps the younger generation has not experienced “Y2K” technical problems because they are still children. The millennium bug is about 22 years until today. I think many people have forgotten. The digital world disaster is similar to the Old Testament description of the earth flood, and God instructed to build an ark to save the species.

Fundamental design weakness: On a 32-bit Linux system, the maximum value that time_t can represent is 0x7ffffffff. When time_t takes the maximum value, it means that the system time is 2038-01-19 03:14:07, but when the clock keep going, time_t will overflow and become A negative value. At this time, the system time will start over and the operating system and upper-layer software will run incorrectly.

IoT current status 2021: The trend by today – 8-bit and 16-bit MCUs had been the hardware of choice for IoT devices, but 32-bit MCUs are now becoming increasingly popular, leading to many manufacturers using two different powered processes in devices. Therefore, your RTOS should be scalable in order to manage any future MCU upgrades.

Reports indicate that there will be 35.82 billion IoT devices installed worldwide by 2021 and 75.44 billion by 2025.

Remedy: In order to remedy this technical limitation. Software developer require to use GNU C Library 2.32 and Musl libc 1.2 to build user space for 64-bit time_t.
Musl, a C standard library, is mainly used on operating systems based on the Linux kernel. The target is embedded systems and mobile devices. It is released under the MIT license. The author is Rich Felker. The purpose of developing this library is to write a clean, efficient, and standard-compliant C standard library.

Expectation: We pass a new challenge token to the younger generation, because they have grown up now. It’s your turn.

About WRECK DNS vulnerabilities – 15th Apr 2021

Background: DNS security awareness awaken by expert conduct a simple DNSsteal to do a demonstration show how to exploit unknown function feature on DNS function in few years ago.
On April 2021, cyber security product vendor with security experts announce that a unknown TCP/IP Stack weakness in IoT.
The difference in between DNS misuse function (DNSsteal) and techincal problem announced by vendor this month was that this time it is a design weakness of IoT TCP/IP stack.

Vulnerability details: So called WRECK, it affects at least four common TCP/IP stacks—FreeBSD, IPNet, NetX, and Nucleus NET—that are used in Internet of Things (IoT). The specify flaws could be abused to perform denial of service (DoS) attacks, to execute code remotely and or take victim devices offline. For details, please refer to link –

My Comment: This IoT vulnerabilities crisis awaken IoT vendor to enhance their IoT access control function. Build trust connection function to external peer. So it will avoid the abnormalis traffic connect to your device and reduce the risk. Perhaps DNS protection should provides from service provider simultaneously.