ISA ISA-IEC-62443 Actual Questions

Multiuser accounts and shared passwords are accounts and passwords that are used by more than one person to access a system or a resource. They inherently carry the risk of unauthorized access, which means that someone who is not authorized or intended to use the account or password can gain access to the system or resource, and potentially compromise its confidentiality, integrity, or availability. For example, if a multiuser account and password are shared among several operators of an industrial automation and control system (IACS), an attacker who obtains the password can use the account to access the IACS and perform malicious actions, such as changing the system settings, deleting data, or disrupting the process. Multiuser accounts and shared passwords also make it difficult to track and audit the activities of individual users, and to enforce the principle of least privilege, which states that users should only have the minimum level of access required to perform their tasks. Therefore, the ISA/IEC 62443 standards recommend avoiding the use of multiuser accounts and shared passwords, and instead using individual accounts and strong passwords for each user, and implementing authentication and authorization mechanisms to control the access to the IACS. References:

• ISA/IEC 62443-3-3:2013 - Security for industrial automation and control systems - Part 3-3: System security requirements and security levels1
• ISA/IEC 62443-2-1:2009 - Security for industrial automation and control systems - Part 2-1: Establishing an industrial automation and control systems security program2
• ISA/IEC 62443 Cybersecurity Fundamentals Specialist Training Course3

Shared passwords and multiuser accounts pose specific risks, notably unauthorized access and privilege escalation. In ISA/IEC 62443's framework, these practices are discouraged because they complicate the attribution of actions to individual users and increase the likelihood that accounts can be used beyond their intended scope. Unauthorized access occurs when individuals exploit the shared nature of an account to gain entry to systems or data that they should not access. Privilege escalation can happen when users leverage shared accounts to perform actions at higher permission levels than those assigned to their personal accounts. Conversely, buffer overflows and race conditions are types of vulnerabilities or programming errors, not directly associated with the risks of multiuser accounts or shared passwords.

"A common pitfall is to attempt to initiate a CSMS program without at least a high-level rationale that relates cyber security to the specific organization and its mission."

A CSMS program is a Cybersecurity Management System program that follows the IEC 62443 standards for securing industrial control systems (ICS)1. A common pitfall when initiating a CSMS program is D. Immediate jump into detailed risk assessment. This is because a detailed risk assessment requires a clear definition of the system under consideration (SuC), the allocation of IACS assets to zones and conduits, and the identification of threats, vulnerabilities, and consequences for each zone and conduit2. These steps are part of the assess phase of the CSMS program, which is the first phase of the security program development process2. However, before starting the assess phase, it is important to have the management team’s support to ensure the CSMS program will have sufficient financial and organizational resources to implement necessary actions2. Therefore, jumping into detailed risk assessment without having the management buy-in is a common mistake that can jeopardize the success of the CSMS program.

 Layer 1 of the ISO/OSI protocol stack is the physical layer, which provides the means of transmitting and receiving raw data bits over a physical medium. It defines the electrical and physical specifications of the data connection, such as the voltage levels, signal timing, cable types, connectors, and pin assignments. It does not perform any data encryption, routing, end-to-end connectivity, framing, error checking, or user applications. These functions are performed by higher layers of the protocol stack, such as the data link layer, the network layer, the transport layer, and the application layer. References: ISO/IEC 7498-1:1994, Section 6.11; ISA/IEC 62443 Cybersecurity Fundamentals Specialist Study Guide, Section 3.1.12

One of the reasons for the increase in attacks on IACS is the availability of information and tools that can be used to exploit vulnerabilities in these systems. The Internet provides a platform for hackers, researchers, and activists to share their knowledge and techniques for compromising IACS. Some examples of such information and tools are:

• Stuxnet: A sophisticated malware that targeted the Iranian nuclear program in 2010. It exploited four zero-day vulnerabilities in Windows and Siemens software to infect and manipulate the programmable logic controllers (PLCs) that controlled the centrifuges. Stuxnet was widely analyzed and reported by the media and security experts, and its source code was leaked online1.
• Metasploit: A popular penetration testing framework that contains modules for exploiting various IACS components and protocols. For instance, Metasploit includes modules for attacking Modbus, DNP3, OPC, and Siemens S7 devices2.
• Shodan: A search engine that allows users to find devices connected to the Internet, such as webcams, routers, printers, and IACS components. Shodan can reveal the location, model, firmware, and configuration of these devices, which can be used by attackers to identify potential targets and vulnerabilities3.
• ICS-CERT: A website that provides alerts, advisories, and reports on IACS security issues and incidents. ICS-CERT also publishes vulnerability notes and mitigation recommendations for various IACS products and vendors4. These sources of information and tools can be useful for legitimate purposes, such as security testing, research, and education, but they can also be misused by malicious actors who want to disrupt, damage, or steal from IACS. Therefore, IACS owners and operators should be aware of the threats and risks posed by the Internet and implement appropriate security measures to protect their systems. References:
• The increase in attacks on Industrial Automation and Control Systems (IACS) can be attributed to several factors, including: A.Use of proprietary communications protocols:These can pose security risks because they may not have been designed with security in mind and are often not as well-tested against security threats as more standard protocols. C.Knowledge of exploits and tools readily available on the Internet:The availability of information about vulnerabilities and exploits on the internet has made it easier for attackers to target IACS.
• The other options, B and D, are incorrect because: B. The move towards commercial off-the-shelf (COTS) systems, protocols, and networks actually increases risk because these systems are more likely to be known and targeted by attackers, compared to proprietary systems which might benefit from security through obscurity. D. There is actually an increase in risk with more personnel with system knowledge because it enlarges the attack surface – each individual with system knowledge can potentially become a vector for an attack, either maliciously or accidentally.