Security Focus: VMware vCenter Server remote code execution vulnerability in vSphere client (CVE-2021-21972) – 24th Feb, 2021

Background: The earlier release of vRealize Operations Manager with vCenter Server was shipped with the NGC plugin. The new vRealize Operations Manager plugin in vCenter Server, provides a mechanism to provide specific metrics and high-level information about data centers, datastores, VMs, and hosts, for the vCenter Server and vSAN. The plugin is supported only in the HTML5 version of the vSphere Client.

Reminder: If an administrator installs a plug-in in an instance of the vSphere Web Client, the plug-in can execute arbitrary commands with the privilege level of that administrator.

Vulnerability details: The vSphere Client (HTML5) contains a remote code execution vulnerability in a vCenter Server plugin.

Scenario: Perhaps attacker can make us of tool written by python and create a zip file that contains files with directory traversal characters in their embedded path. If a program and/or library does not prevent directory traversal characters then tool can be used to generate zip files that, once extracted, will place a file at an arbitrary location on the target system.

Workaround: The affected vCenter Server plugin for vROPs is available in all default installations. It is recommended to disabled immediately. Official recommendation:

Remediation: To remediate CVE-2021-21972 apply the updates. Please refer to link –

Design weakness on RPC service awaken your alert! (24th Feb 2021)

Background: Remote Procedure Call (RPC) TCP port 135 is used for client-server communications by Microsoft Message Queuing (MSMQ) as well as other Microsoft Windows/Windows Server software.Allowing unrestricted RPC access on TCP port 135 can increase opportunities for malicious activities such as hacking (backdoor command shell).

Recent RCP-related vulnerabilities in software product:
CVE-2020-11635: The Zscaler Client Connector prior to 3.1.0 did not sufficiently validate RPC clients, which allows a local adversary to execute code with system privileges or perform limited actions for which they did not have privileges.

Current status: This vulnerability could allow an attacker who has local access to the user’s machine to elevate privileges and potentially compromise the user’s machine. There are no known instances of this vulnerability being exploited at this time and this vulnerability is not remotely exploitable.

Official announcement and remedy solution

Would it be possible? Malware attack Apple M1 chip? – 21st Feb 2021

Preface: Can M1 chip run Windows? It is unsupported. the M1 decided not to use Boot Camp. Therefore it is not possible running Windows on Macs!

Background: So called “System on a Chip”, M1 integrates several different components, including the CPU, GPU, unified memory architecture (RAM), Neural Engine, Secure Enclave, SSD controller, image signal processor, encode/decode engines, Thunderbolt controller with USB 4 support.

Malware attack Apple M1 chip? Would it be possible?
According to record, GoSearch22 has signed with an Apple developer ID on November 23rd, 2020. GoSearch22 is the name of a potentially unwanted application (PUA) that functions as adware. Apple has (now) revoked the certificate. Since M1 systems will be running Big Sur which requires code to be signed, we assume the malware will be signed (and thus leverage the “signed” tag).

Alert: Security expert confirm that malware/adware authors are working out ways to attack M1. He found that if malware authors are natively compiling code for M1 systems. This code will be found within a universal/fat binary such their malicious creations will retain compatibility with older (Intel-based).


Have you worry your source code will be stolen by someone else? – – Vulnerability Note VU#240785 (18th Feb 2021)

Preface: Bitbucket’s advantage over GitHub used to be that both Git and Mercurial repository hosting were available with Bitbucket.

Background: If you are a Jira user, you can import your existing Git repositories into Bitbucket. Jira Software and Bitbucket does integrate and will work with third party builders like Jenkins. However, the deepest integrations are with Bamboo and using Jira Software and Bitbucket.

Vulnerability details: Atlassian Bitbucket on Windows is vulnerable to privilege escalation due to weak ACLs. For more details, please refer to link or attached diagram –


Ref: DLLSpy (Dynamic) – DLLSpy scans the loaded modules figure out loaded module list. Then it checks if any of those modules could be hijacked by trying to write to their file location on disk and then checking if they could be overwritten. This happens after the duplication of the access token for browser, which is a weak token. Attacker do that in order to test whether he have write permission to the DLL location and the DLL itself as a regular user.

CVE-2021-21305 – CarrierWave (18th Feb 2021)

Preface: CarrierWave provides a simple and extremely flexible way to upload files from Ruby applications. Ruby On Rails Companies Websites are popular. It covered all your familiar areas – Airbnb, Groupon, GitHub, Twitter, Zendesk, Bloomberg…

Background: CarrierWave is an open-source RubyGem which provides a simple and flexible way to upload files from Ruby applications. In CarrierWave before versions 1.3.2 and 2.1.1, there is a code injection vulnerability.

Vulnerability details: The “#manipulate!” method inappropriately evals the content of mutation option(:read/:write), allowing attackers to craft a string that can be executed as a Ruby code. If an application developer supplies untrusted inputs to the option, it will lead to remote code execution(RCE). For more details, please refer to diagram.

Workaround: It is recommended to stop supplying untrusted input to #manipulate!’s mutation option.

Remedy: upgrade to 2.1.1 or 1.3.2.

Reference: RubyGems is a package manager for Ruby. It provides a standard format “gem” for distributing Ruby programs and libraries. It is designed to conveniently manage gem installation tools and servers for distributing gems. This is similar to Python’s pip.

Embedded TCPip stacks memory corruption vulnerabilities, there are plenty of companies current status not confirmed – 16-02-2021

Preface: Embedded TCP/IP stacks have memory corruption vulnerabilities (Vulnerability Note VU#815128) – Siemens, SUSE Linux, iSCSI, FNet, Micrichip Technology, Weinert Automation, Abbott Labs, ….
There are plenty of companies current status not confirmed.

Background: CERT Coordination Center alert to public on December 2020 that the TCP/IP stacks has memory corruption vulnerabilities. Therefore, this design weakness is impacting the IoT world. Forescout Research Labs discovered 33 vulnerabilities impacting millions of IoT, OT and IT devices that present an immediate risk for organizations worldwide. So called amnesia33. A closer look of vulnerability checklist, you will find that there are plenty of vulnerabilities result deny of service & info leak. Furthermore, CVE-2020-24336 & CVE-2020-24338 flaw will allow attacker to do a remote code execution (RCE).

Security focus: The serious impact is RCE caused by defects in the DNS function shown on report issued by Forescout. The flaw shown that the processes DNS queries and responses has plenty of issues. Refer below:

  • no check on whether a domain name is nukk-terminated.
  • DNS response data length is not checked
  • DNS queries and response (set in DNS header) is not checked against the data present
  • length byte of a domain name in a DNS query and response is not checked and is used for internal
    memory operations.

Current status: We are still waiting for vendor response. For detail, please refer to link –

Node-ps package encountered design weakness – CVE-2020-7785 (11th Feb 2021)

Preface: Node.js is an application runtime environment that enables using JavaScript for building server-side applications that have access to the operating system, file system, and everything else to be fully-functional. There are total 8 Top companies that rely on Node.js.

Background: Using Node.js allows organizing full stack JavaScript development ensuring the speed and performance of the application. Furthermore you are queries that how to check a process is running by the process name? Perhaps, it can use the ps-node package.

Vulnerability details: Node-ps package encountered design weakness. It found a injection point in lib/index.js. Perhaps it should avoid using the exec() function and use execFile() instead. The execFile() function will execute a single command and does not spawn a shell by default which makes it safer than exec().

Remark: By default, pipes for stdin, stdout, and stderr are established between the parent Node.js process and the spawned subprocess.

Official announcement:

The design weakness was beyond vendor control. VMware Vulnerabilities (CVE-2021-21976) – 12th Feb 2021

Preface: With vSphere Replication, you can set up replication of VM from the source site to the target site, monitor and manage the replication status, and restore VM on the target site.

Background: vSphere Replication is an alternative to storage-based replication. It protects virtual machines from partial or complete site failures by replicating the virtual machines from a source site to a target site. Some configuration files contain settings that affect the security of vSphere Replication (see below):
– The default system configuration of the vSphere Replication Management server.
– The configuration file for the embedded database.

Vulnerability details: Attacker with administrative access in vSphere Replication can execute shell commands on the underlying system. Successful exploitation of this issue may allow authenticated admin user to perform a remote code execution.
Official announcement:

Remark: If html page lack of sanitization function and causes the injection of command. The impact may unforeseeable.

CVE-2021-1732 Win32k Elevation of Privilege Vulnerability (11th Feb 2021)

Preface: There are many reasons to encounter win32k.sys problems. Most issues related to SYS files involve blue crashes in past.

Background: win32k.sys is a valid program that is required to run at startup.The Graphics Device Interface Provides functionality for outputting graphical content to monitors, printers and other output devices. It resides in gdi.exe on 16-bit Windows, and gdi32.dll on 32-bit Windows in user-mode. Kernel-mode GDI support is provided by win32k.sys which communicates directly with the graphics driver. What is the difference if System Call filtering had been enabled. This may be examined by using the W32pServiceTableFilter instead.

Vulnerability details: A zero day vulnerability occurred in win32k callback, it could be used to escape the sandbox of Microsoft IE browser or Adobe Reader on the lasted Windows 10 version.

Attack Vector: Tricking a legitimate user into opening a malicious document

Impact: Elevation of Privilege

Official announcement –

CVE-2021-3347 – An issue was discovered in the Linux kernel through 5.10.11 (use-after-free) – 8th Feb 2021

Preface: Unlike Windows or MacOS which push out software updates to users automatically, it is up to developers to look for Linux kernel updates on their own.

Background: The futex() system call provides a method for waiting until a certain condition becomes true. It is typically used as a blocking construct in the context of shared-memory synchronization.

  • in the user-space fastpath a PI-enabled futex involves no kernel work
    (or any other PI complexity) at all. No registration, no extra kernel
    calls – just pure fast atomic ops in userspace.

Vulnerability details: An issue was discovered in the Linux kernel through 5.10.11. PI futexes have a kernel stack use-after-free during fault handling, allowing local users to execute code in the kernel, aka CID-34b1a1ce1458. See whether attached diagram can give you hints on the matter.

Remedy: Fix fault handling in futex_lock_pi. Official details refer to following link –

Comments: Perhaps you have doubts when aware this vulnerability? Can we maintain this statement say, Linux is secure than windows OS. But don’t forget that hacker likes Microsoft.