Remote Access Security: The Dangers of VPN

Dave Greenfield
April 26, 2021

Millions of people worldwide are still working remotely to support shelter-in-place requirements brought on by the pandemic. For many workers, a remote workstyle is a preference that will likely become a more permanent arrangement. Enterprises have responded by expanding their use of VPNs to provide remote access to the masses, but is this the right choice for long-term access? 

Aside from enabling easy connectivity, enterprises also must consider the security of VPNs and whether their extensive use poses risks to the organization. (Spoiler alert: they do.) Long-term use alternatives must be considered due to VPNs’ failures where remote access security is concerned. One prominent alternative is Secure Access Service Edge (SASE) platforms with embedded Zero Trust Network Access (ZTNA) that alleviate the security dangers and other disadvantages of VPN. 

VPNs Put Remote Access Security at High Risk

In general, VPNs provide minimal security with traffic encryption and simple user authentication. Without inherent strong security measures, they present numerous risk areas: 

VPN users have excessive permissions 

VPNs do not provide granular user access to specific resources. When working remotely via VPN, users access the network via a common pool of VPN-assigned IP addresses. This leadto users being able to “see” unauthorized resources on the network, putting them only a password away from being able to access them. 

Simple authentication isn’t enough

VPNs do provide simple user authentication, but stronger authentication of users and their devices is essential. Without extra authentication safeguards – for example, multi-factor authentication, or verification against an enterprise directory system or a RADIUS authentication server – an attacker can use stolen credentials and gain broad access to the network. 

Insecure endpoints can spread malware to the network 

There is no scrutiny of the security posture of the connecting device, which could allow malware to enter the network. 

The full security stack doesn’t reach users’ homes

Enterprises have built a full stack of security solutions in their central and branch offices. This security doesn’t extend into workers’ homes. Thus, to maintain proper security, traffic must be routed through a security stack at the VPN’s terminus on the network. In addition to inefficient routing and increased network latency, this can result in having to purchase, deploy, monitor, and maintain security stacks at multiple sites to decentralize the security load. 

VPN appliances are a single point of failure –

For enterprises that support a large remote workforce connecting via VPN, there is high risk of business interruption if a VPN fails or is incapacitated, such as through a DoS attack. No appliance means no access for anyone who would connect to it. 

Some VPNs have known vulnerabilities –

Enterprises are responsible for monitoring for vulnerabilities and updating and patching devices as needed. Serious flaws that go unpatched can put organizations at risk. For example, in March 2020, it was reported that Iranian hackers were leveraging VPN vulnerabilities to install backdoors in corporate and government networks. The attack campaign targeted several highprofile brands of VPNs. 

 VPNs add to overall network complexity 

Adding one or more VPNs to the data center to manage and configure adds to the overall complexity of network management, which could ultimately lead to greater security vulnerabilities. 

 Network managers have limited visibility into VPN connections 

The IT department has no visibility into what is happening over these appliances. The user experience suffers when problems occur, and no one knows the root cause. 

Split tunneling provides opportunity for attack 

To alleviate VPN capacity constraints, organizations sometimes utilize split tunneling. This is a network architecture configuration where traffic is directed from a VPN client to the corporate network and also through a gateway to link with the Internet. The Internet and corporate network can be accessed at the same time. This provides an opportunity for attackers on the shared public network to compromise the remote computer and use it to gain network access to the internal network. 

VPNs Have Other Drawbacks

In addition to the security issues, VPNs have other drawbacks that make them unsuitable for long-term remote access connectivity. For example, an appliance has capacity to support a limited number of simultaneous users. Ordinarily this isn’t a problem when companies have 10% or less of their employees working remotely, but when a much higher percentage of workers need simultaneous and continuous access, VPN capacity can be quickly exceeded. This requires the deployment of more and/or larger appliances, driving costs and management requirements up considerably. Companies use workarounds like split tunneling to address lack of scalability, which can degrade traffic visibility and security. 

A Better Long-term Solution for Secure Remote Access

VPNs are no longer the only (or best) choice for enterprise remote accessGartner’s Market Guide for Zero Trust Network Access (ZTNA) projected that by 2023, 60% of enterprises will phase out VPN and use ZTNA instead. The main driver of ZTNA adoption is the changing shape of enterprise network perimeters. Cloud workloads, work from home, mobile, and on-premises network assets must be accounted for, and point solutions, such as VPN appliances, aren’t the right tool for the job. 

The main advantage of ZTNA is its granular control over who gains and maintains network access, to which specific resources, and from which end user devices. Access is granted on a least-privilege basis according to security policies.  

But Zero Trust is only one part of a remote access solution. There are performance and ongoing security issues that aren’t addressed by ZTNA standalone offerings.  For example, all traffic still needs to undergo security inspection before proceeding to its destination. This is where having ZTNA fully integrated into a Secure Access Service Edge (SASE) solution is most beneficial.  

SASE converges ZTNA, NextGen firewall (NGFW), and other security services along with network services such as SD-WAN, WAN optimization, and bandwidth aggregation into a cloud-native platform. Enterprises that leverage a SASE networking architecture receive the benefits of ZTNA, plus a full suite of converged network and security solutions that is both simple to manage and highly scalable. The Cato SASE solution provides all this in a cloud-native platform.

Cato’s SASE solution enables remote users, through a client or clientless browser access, to access all business applications, via secure and optimized connection. The Cato Cloud, a global cloud-native service, can scale to accommodate any number of users without deploying dedicated VPN infrastructure. Remote workers connect to the nearest Cato PoP – there are more than 60 PoPs worldwide – and their traffic is optimally routed across the Cato global private backbone to on-premises or cloud applications. Cato’s security services protect remote users against threats and enforces application access control. 

In short, the Cato SASE platform makes it quick and easy to give optimized and highly secure access to any and all remote workers. For more information on how to support your remote workforce, get the free Cato eBook Work From Anywhere for Everyone. 

 

 

Dave Greenfield

Dave Greenfield is a veteran of IT industry. He’s spent more than 20 years as an award-winning journalist and independent technology consultant. Today, he serves as a secure networking evangelist for Cato Networks.