Category Archives: 2023

Whether it is the last round of remediation on CVE-2022-26373? Intel’s Enhanced Indirect Branch Restricted Speculation (eIBRS) – 6th Feb 2023

Preface: CVE-2022-26373 technical detail has released to public on 9th Aug 2022. Till end of Jan, 2023 it still has update on this vulnerability. For example, Red Hat fixed this vulnerability in their product Enterprise Linux 7 on 3rd Nov 2022. Since then it conducting the remediation to their product line. Perhaps the remediation on 24th Jan 2023 to Red Hat Virtualisation 4 for Red Hat Enterprise Linux 8 is the final round.
Looks like this is a CPU vendor specific bug. As a result, some vendors have stated that their products are not affected by this vulnerability. Whether it a absolute answer? All will depends on the use of CPU processor brand.

Background: From technical point of view, Indirect Branch Restricted Speculation (IBRS) is an indirect branch control mechanism that restricts speculation of indirect branches. See below for technical details.
CPUID.(EAX=7H,ECX=0): If EDX[26] is 1, it means support IBRS and IBPB,
OS can write IA32_SPEC_CTRL0 and IA32_PRED_CMD0 to control the behavior of indirect branch predictor.
IBRS finally failed to enter the kernel due to function problems, however when when the vm is switched. It can get into kernel. This weakness found in 2018 earlier stage.

Vulnerability details: A flaw was found in hw. In certain processors with Intel’s Enhanced Indirect Branch Restricted Speculation (eIBRS) capabilities, soon after VM exit or IBPB command event, the linear address following the most recent near CALL instruction prior to a VM exit may be used as the Return Stack Buffer (RSB) prediction.
Non-transparent sharing of return predictor targets between contexts in some Intel(R) Processors may allow an authorized user to potentially enable information disclosure via local access.

Official announcement – For details, see URL – https://access.redhat.com/security/cve/cve-2022-26373

What is the value of the Trusted Execution Environment (TEE) ? (20th JAN 2023)

Preface: Some said, found malware lets cybercriminal remotely manipulate your Android.

Background: The full name of TEE is trusted execution environment, which is an area on the CPU of mobile devices (smart phones, tablets, smart TVs). The role of this area is to provide a more secure space for data and code execution, and to ensure their confidentiality and integrity.

Other TEE operating systems are traditionally supplied as binary blobs by third-party vendors or developed internally. Developing internal TEE systems or licensing a TEE from a third-party can be costly to System-on-Chip (SoC) vendors and OEMs.

Trusty is a secure Operating System (OS) that provides a Trusted Execution Environment (TEE) for Android. A Trusty application is defined as a collection of binary files (executables and resource files), a binary manifest, and a cryptographic signature. At runtime, Trusty applications run as isolated processes in unprivileged mode under the Trusty kernel.

Technical details: According to headline news, a new Android malware named ‘Hook’ is being sold by cybercriminals, boasting it can remotely take over mobile devices in real-time using VNC (virtual network computing). said bleepingcomputer news.

For details, please refer to URL – https://www.bleepingcomputer.com/news/security/new-hook-android-malware-lets-hackers-remotely-control-your-phone/

Speculation: If this reported malware achieves their goals, do you think they will relies on vulnerability such as CVE-2023-21420?

Solution: To avoid Android malware, you should only install apps from the Google Play Store.

Here’s wishing you a Happy Chinese New Year 2023.

Headline news: FAA system outage disrupts thousands of flights across U.S. (12th Jan 2023)

Preface: Thousands of flights across the U.S. were delayed Wednesday after a Federal Aviation Administration pilot alert system failed overnight, prompting a nationwide halt to departures. said CNBC news.

Headline news – https://www.cnbc.com/2023/01/11/faa-orders-airlines-to-pause-departures-until-9-am-et-after-system-outage.html

Background: The Department of Homeland Security published the following opinion piece four years ago.

The GPS system is now considered a “crosssector dependency” for the Department of Homeland Security’s (DHS) 16 designated critical infrastructure sectors. GNSS is vulnerable to jamming and natural interference. When GNSS is denied, PNT information can be seriously affected in ways that increase risks to the safety of navigation.

My observation: Perhaps the incident was not caused by a cyber attack. But industry experts know that the overall system architecture will be combined with OS vendor-dependent drivers.

For example: if the driver is written as a specify standard driver using user-mode extensions is not recommended because this model will likely require more memory usage. However, this specify standard is available on all platforms and it is strongly recommended to use the driver written in user mode.

So, the function is not only OS specific, it also including 3rd party vendor to do the software development. As a matter of fact, aero industry is a special zone. The current computer technology is also involving such zone. In computer world nowadays, the patch to vulnerability is common. So, who can say that this is a trust zone and it is without vulnerability forever.