Remote Desktop Access
Managing Cyber Risk with Zero Trust Network Access
Compare, contrast, merge, enhance. How the Purdue model for Industrial Control Systems interacts with the Zero Trust Network Architecture.
Remote Desktop: The Current State and Risks
For many businesses and organisations around the world, Remote Desktop Access has become an essential tool for both providing and maintaining services. IT personnel and other technical workers depend on the ability to remotely access certain machines to perform their job function. However, without adequate modern security systems and practices it is no longer a minor inconvenience when a cyber breach occurs on these remotely accessed devices. The damage can be immeasurable and even ruinous for people and businesses.
It is becoming increasingly important for businesses and organizations to implement modern, cybersecurity tools that mitigate threats and turn the tables on the unmanaged cyber risk that can result from Remote Desktop Access. A future-forward approach to cybersecurity practices can help protect businesses, organizations, and public and shareholder interests.
Most organizations are still using antiquated technology solutions to enable Remote Desktop Access and are increasingly unable to contend with sophisticated malicious actors. Even more problematic is the way most conventional security solutions are unable to accommodate Remote Desktop Access in a manner that ensures only authorized and authenticated access can be gained.
When Remote Desktop Access is performed via a corporate Virtual Private Network (VPN), the risk increases with inbound and outbound network gateways wide open. In this case, there’s nothing stopping a local attack or breach from becoming widespread.
Implementing secure processes and protocols for Remote Desktop Access has historically increased the burden on IT resources or required increased technical capability from the end-user or operator. Adopting a modern approach to cybersecurity can help ensure only the authorized person or persons are able to gain Remote Desktop Access while balancing convenience, control, and security.
Methods and Tools for Remote Access
Remote Desktop Services and Solutions have had many iterations over the years but were first introduced to the world in the late 90s with Microsoft’s Remote Desktop Protocol (RDP) as part of the Windows NT 4.0 Server, Terminal Server Edition1. One of the original intentions of RDP was to allow less powerful machines to remote into more powerful Microsoft Servers to perform tasks.
There are now many common tools for achieving remote access. Windows RDP is a widely adopted method of Remote Desktop Access that works on both Windows and Linux operating systems. Other tools that enable Remote Desktop Access include remote access via VPN, Desktop Sharing, and other remote control and systems management tools. TeamViewer, RemotePC, and LogMeIn are all examples of the various types of Remote Access Software and Tools (RATs) for commercial use that exist today. Each method of Remote Desktop Access brings with it a tradeoff between security and convenience.
Today, being able to remotely access machines brings with it immense cost savings and efficiency for many organizations, especially in a 24/7, global society. However, this constant connectivity also presents numerous risks and challenges, especially in the context of cybersecurity.
How Does Remote Desktop Access Work?
Remote Desktop Access enables someone to connect to a host machine from their client machine located anywhere in the world over the internet, gaining control of the interface and access to applications and file systems.
Whether it’s 5 or 5000 km away, connecting from a home or office device lets a user access the host machine without having to physically be there. The host machine could be a desktop, computer system, server, or virtual environment.
Business Application of Remote Desktop Access
Remote Desktop Access is a now widely adopted concept and network functionality, especially for it’s obvious business applications (most recently being leveraged by IT organizations in response to the COVID-19 pandemic2). The network functionality is being put to work across industry verticals. Remote Desktop Access helps technicians gain access to the machines they need to perform their duties without having to physically be on-premise.
Remote Technical and Customer Support
People most commonly associate Remote Desktop Access with providing remote technical support to employees or customers. That means an IT, technical, or other support representative gains access to a customer’s host machine over the internet. From their own machine, the IT or technical support person now has control over the customer host device and can provide any necessary support or maintenance. In gaining Remote Desktop Access, the support representative also has access to the applications, file system, and data stored on the host machine.
Remote Desktop Access for Server Applications, Maintenance, and Deployment
The host device does not always have to be a PC and in fact, Remote Desktop Access is commonly used by IT technicians as a way of accessing servers or virtual desktop environments without having to physically be in the server room. These machines can be critical to corporate infrastructure, host data and applications, or they can be virtual environments used to develop, test, and deploy new applications.
Remote Desktop Access for Legacy Applications
Legacy applications are typically obsolete or outdated systems that either perform a critical function or are embedded within critical infrastructure. These applications or the systems they can run on are typically unable to stay up to date with the latest operating systems or security software. While a suitable replacement could be under development for a legacy environment, the current instance performs a specific function and may need to be securely accessed by remote technicians and employees.
Remote Access for SCADA Systems
Remote Desktop Access can be an essential tool for technicians to interact with Supervisory Control and Data Acquisition (SCADA) systems, be it in industrial, energy, manufacturing or the public sector. Remote access to a SCADA system by employees, vendors, partners, or third parties is often operationally important. These SCADA systems can be found in public utilities like energy or water treatment and provide a control system architecture that enables the supervision and control of machines and processes by technicians.
Remote Desktop Risks And Threats
There are numerous cyber attack vectors and vulnerabilities that come with Remote Desktop Access and other Remote Access Software and Tools. One of the most prominent cybersecurity issues is the use of shared accounts and access credentials. For example, when Remote Desktop Access is achieved using a Remote Access Trojan (also known as a RAT), the attack is direct remote access and the shared credentials are compromised. If Windows RDP is used, it can lead an attacker to accessing an entire network, especially when the system is exposed to the Internet.
No matter the type of tools used to achieve Remote Desktop Access, the variety in the type of cyber attacks that can be mounted presents a persistent threat.
A Lack of Password Protection and Authentication
Whether a malicious actor has guessed a password, intercepted it, or retrieved it from a database or through a brute-force attack, the absence of Multi-Factor Authentication could allow free reign over a system. Weak passwords could be anything from something simplistic, common across accounts, shared with other users (technicians and employees), or previously compromised in a data breach. A strong Multi-Factor Authentication policy could be the difference between getting hacked or not.
Credential Stuffing Attacks
When a credential stuffing cyber attack is performed, the malicious actor uses a list of stolen account credentials to try and gain access to a system. The lists can contain usernames, emails, passwords, or other login credentials, which are used to gain unauthorized access to the targeted system or account. The process of mounting this type of attack is usually automated through the use of bots. This type of attack is possible as many users tend to reuse credentials across both personal and work accounts.3
Employees can unintentionally present security risks, whether they fall victim to social engineering, introduce a small oversight, or they themselves become the victim of compromise, such as through a data breach.
If you use multiple identities (multiple passwords, multiple sign-ins) in your day-to-day work in your company, your team will become accustomed to this, and its challenging to train them to recognise spear-phishing.
During an actor-in-the-middle attack4 on a remote session, a malicious actor will try to intercept communication between systems. The intent could be anything from intercepting or harvesting credentials, to spreading malware or ransomware within an organization.
Denial of Service Attacks
Another Remote Desktop Access attack method used by malicious actors is to determine the IP address and open ports on a host machine where a brute-force attack5 is mounted and designed to reveal credentials for remote access. Often, the byproduct of mounting such an attack, intended or not, is a denial of service (DOS)6, which not only disrupts the function of the host machine, but can prevent authorized users from accessing it.
Software Based Permissions Vulnerabilities
Applications require permissions7 that are granted by the administrator of a machine, this includes RATs. From time to time there are bugs in these permissions that result in vulnerabilities that can be exploited by malicious actors. One of the most recent and relevant examples was a critical exploit discovered in TeamViewer’s administrator permissions8 that could have allowed malicious payloads to be persistently executed every time the service ran. Fortunately, this vulnerability in TeamViewer has since been patched.
Remote Access Common Vulnerabilities and Exposures (CVE)
Common Vulnerabilities and Exposure (CVE) is a list of publicly-known security vulnerabilities, exposures, and exploits.9 This list provides a common point of reference for IT administrators to help secure systems. The list of CVEs is constantly expanding and regularly updated as new vulnerabilities and exploits are discovered. Remote Desktop Access exploits through Windows RDP, Desktop Connection, and more are included in this list. For example a number of Denial of Service CVE’s for Windows RDP were discovered in 2020.10
There is a pressing need to mitigate threats against remotely accessed machines and the risk and consequences that go along with them.
Remote Desktop Access in a Corporate Environment
In most enterprise and business corporate network environments, Remote Desktop Access tasks are actually performed over a corporate VPN which can amplify cyber risk. Traditionally the VPN served as a way to create a secure tunnel to the host machine that needed to be accessed. However, the method of attack and risk climate has changed significantly over the years and if remote access is achieved through a VPN the client machine, host machine, or network, the risk is no longer localized and can spread across environments.
When an attacker gains access to a client machine, remote host machine, or corporate VPN, that access may be trusted by default, which means the infiltration can go undetected. The VPN by its very nature is an all-or-nothing perimeter-based security solution. It’s either access to the entire network or none of the network, which is why lateral traversal within an organization’s network is possible.
Securing Remote Desktop Access to Manage Cyber Risk and Mitigate Threats
Remote Desktop Access has become an essential function for most organizations, however, with the frequency of cyber attacks only accelerating,11 exceptional security around Remote Desktop Access is not discretionary. Legacy applications and SCADA systems for example have come under frequent attack. The breach of the Florida water treatment plant in 202112 is an example of the security and public risk unsecured Remote Desktop Access presents.
IT Organizations need to provide Remote Desktop Access to specific host machines for specific users, even those outside the organization like contractors, vendors, and third parties. In order to secure these environments an authorization, authentication, access approach can help manage cyber risk more effectively through a Zero Trust Architecture.
What is Zero Trust Security
Zero Trust Network Access and Security means switching from outdated perimeter-based (firewall and VPN) models of access to an identity-based model of access. That means authorization, authentication, and access privileges are determined based on the identity of a person (user) and the identity of a resource (device/machine).
Identity-based access means decoupling identity from a corporation or organization and binding it to the user, creating a single identity. This allows IT administrators to enforce entitlements and authorizations within the network, effectively segmenting access.
Segmentation of access is simple, more secure, and doesn’t inhibit the accessibility of employees to their work. It does however significantly mitigate the risk of cyber attacks like lateral-traversal within a network, malware, and ransomware. Adopting a modern cloud-native security platform empowers users to work from any device, anywhere in the world while ensuring the organization has granular auditing capabilities, Role Based Access Controls, Privilege Management, and the ability to restrict access with Multi-Factor Authentication.
A Zero Trust Architecture is economical, scalable, and most importantly more secure than conventional methods of network cloaking and inflexible, restrictive policy.
Remote Desktop Access Via Zero Trust
Zero Trust Network Access (ZTNA) ensures IT organizations and administrators have the granular security controls needed to manage per-user authorizations. Limiting end-user, authenticated access to the specific resource, application, or work they need protects the broader corporate network and machines from being exposed to attackers, keeping compromises localized.
When Zero Trust is applied to Remote Desktop Access the risk profile and exposure of applications, systems, networks, and corporate resources is significantly reduced without inhibiting the productivity of the employee or technician who requires access to the host machine. In essence, Zero Trust allows the IT organization to require authentication and authorization from both the user and the designated device. That means a technician must prove their identity before being allowed to gain Remote Desktop Access.
Users are commonly identified via OpenID Connect and SAML, where resources are commonly identified by Client Certificates. Single Sign-On and Multi-Factor Authentication paired with these core tenants of Zero Trust (Authorization, Authentication, and Access) means that strong password policies and authentication methods are innate to the security equation.
Zero Trust ensures that Remote Desktop Access is available to any authorized employee using any designated device without risking the entire network. This method of secure access will also prohibit any unauthorized access to the host machine, by unauthorized users or devices.
Securing Remote Desktop Access With Agilicus AnyX
You can set up 1-click remote access from client to host machine within minutes through Agilicus’ Any X platform. You can enable Remote Desktop Access via a Zero Trust Architecture without configuration on-site and with no change to the host machine or firewall. A detailed step-by-step guide on setting up Agilicus’ Zero Trust platform is available here.
This means that the cyber risk and threats can be heavily mitigated for any resource that must be accessed remotely, whether it’s a server, virtual environment, or physical desktop device hosting a legacy application, or a SCADA system.
How Zero Trust Remote Desktop Access Works with Agilicus
Zero Trust Remote Desktop Access allows any user to connect from any device to the host machine they need to perform their job. The Zero Trust framework ensures access is granted on the basis of identity. Agilicus AnyX features fine-grained controls and authorization for Remote Desktop Access and allows any device to remotely access machines using Windows RDP (Windows and Linux OS). AnyX also features Single-Sign On, Multi-Factor Authentication, full-audit trails, and end-to-end encryption, which only enhances the security surrounding Remote Desktop Access.
Reign in Unmanaged Cyber Risk with Zero Trust Remote Desktop Access
While most applications are modern and accessible through web browsers, there is still a need for native desktop applications and therefore Remote Desktop Access to various machines and resources around the world, whether it is through civilian networks or over corporate VPNs. Remote Desktop Access is widely used by IT professionals and technicians across industry verticals to access servers, perform maintenance, access on premise machines, perform maintenance, and other operational tasks.
Without adequate security or a continuation of the status quo of legacy security practices, Remote Desktop Access creates huge unmanaged cyber risks for IT organizations. Those same remote resources can also be critically important to both private and public interests and in the event of a compromise, there could be significant consequences and very real public safety risks.
Some examples of remote resources that a technician or operator must access are:
• SCADA systems (controlling the power grid, local water treatment facility, etc)
• Servers or virtual machines that host or perform a business function
• Machines that run legacy applications.
• Employee or customer machines and devices to provide support or maintenance
Implementing Zero Trust and its core tenets of authorization, authentication, and access to secure Remote Desktop Access puts the IT organization back in control of its cyber risk profile.
Zero Trust works by trusting no user or device by default and enacts a strict policy that ensures only authorized individuals and devices can gain access to critical resources after authenticating their identity. This differs from a perimeter-based security policy (VPN) where anyone who has gained access to a network is trusted by default.
The security landscape is rapidly evolving, but your requirements of providing convenient and secure access while managing costs aren’t. Agilicus can help you implement an identity-based secure solution that enables Remote Desktop Access for workers while empowering the IT organization with the controls to manage cyber risk for Any Desktop by implementing Authorization, Authentication, and Access.
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1 Deland-Han. “Understanding Remote Desktop Protocol (RDP) – Windows Server.” Microsoft Docs, Microsoft, 24 Sept. 2021, docs.microsoft.com/en-us/troubleshoot/windows-server/remote/understanding-remote-desktop-protocol.
2 Statista. “Remote Access Technology Use Increase 2020, by Region.” Statista, Statista, 15 June 2021, www.statista.com/statistics/1226084/remote-access-technology-use-by-region.
3 “Credential Stuffing Software Attack | OWASP Foundation.” The OWASP® Foundation, 2021, owasp.org/www-community/attacks/Credential_stuffing.
4 “MitM – Glossary | CSRC.” CSRC, 2020, csrc.nist.gov/glossary/term/mitm.
5 “Brute Force Password Attack – Glossary | CSRC.” CSRC, 2020, csrc.nist.gov/glossary/term/brute_force_password_attack.
6 “Denial of Service (DoS) – Glossary | CSRC.” CSRC, 2020, csrc.nist.gov/glossary/term/denial_of_service.
7 “Permissions – Glossary | CSRC.” CSRC, 2020, csrc.nist.gov/glossary/term/permissions.
8 SafeBreach Inc. “TeamViewer Windows Client (V11 to V14) – DLL Preloading and Potential Abuses (CVE-2019-18196).” Safebreach, SafeBreach Inc. 2021, 15 Nov. 2019, www.safebreach.com/blog/2019/teamviewer-windows-client.
9 “CVE – Glossary | CSRC.” CSRC, 2020, csrc.nist.gov/glossary/term/cve.
10 “Security Update Guide – Microsoft Security Response Center.” Microsoft, 2020, msrc.microsoft.com/update-guide/en-US/vulnerability/CVE-2020-16927.
11 Quadros, Sharron. “RDP Attacks on the Rise During COVID-19 Pandemic.” Security Boulevard, Techstrong Group Inc., 6 Jan. 2021, securityboulevard.com/2021/01/rdp-attacks-on-the-rise-during-covid-19-pandemic.
12 Goodin, Dan. “Florida Water Plant Compromise Came Hours after Worker Visited Malicious Site.” Ars Technica, Condé Nast, 18 May 2021, arstechnica.com/gadgets/2021/05/florida-water-plant-compromise-came-hours-after-worker-visited-malicious-site.