Network-Attached Storage (NAS) Security: A Comprehensive Guide

Network attached storage (NAS) is ubiquitous in the enterprise environment, which makes it a lucrative target for cybercriminals. Unfortunately, many NAS systems are poorly protected. Some use outdated protocols or have overly permissive authorized access settings, making them insecure, while others are misconfigured, unencrypted, or sloppily patched, leaving them vulnerable.

Because NAS is connected to the enterprise network, anyone who can access the NAS device might be able to access the network itself, putting the organization and its data at risk. This article provides a comprehensive guide to everything you need to know about network attached storage security.

How Does Network Attached Storage (NAS) Security Work?

To understand how NAS security works, it’s important to first understand how network attached storage works. Unlike direct attached storage, which stores files within a single physical endpoint, NAS stores data in a device that is accessible by many endpoints by connecting it to the network.

That means that NAS security is a microcosm of the larger security picture—everything done to secure the enterprise applies to the NAS as well. Systems must be encrypted, access rights must be carefully defined, patches must be up-to-date, and firewalls must be implemented.

NAS security is not something done in isolation, or something managed by a separate security team. Those responsible for the enterprise security overall should include NAS files in their security actions and stay abreast of ongoing trends in NAS security.

Top NAS Vulnerabilities

The list of cybersecurity risks facing enterprises is long, and most of it applies to network attached storage as well. But many NAS devices are particularly vulnerable due in part to bad user practices. Here are the most common NAS vulnerabilities, according to security software provider Continuity:

• Vulnerable protocols or incorrect protocol settings
• Unaddressed Common Vulnerabilities and Exposures (CVEs)
• Overexposure due to authorized access rights issues 
• Insecure user management and authentication
• Insufficient or incorrect logging

Learn more about Data Storage Security.

6 Steps to Secure Your NAS

NAS must be protected against many threat vectors, including malware, ransomware, human error, disgruntled employees, brute force attacks, and phishing. There’s an entire field devoted to detailed security protections against these threats, but there are a few essential basics to consider for NAS security.

1. Encrypt NAS Devices and Files

Encryption is the most fundamental safeguard for NAS. AES 256-bit algorithms, which require a decryption key to access, provide strong protection. Even if someone is able to breach the system, without an encryption key, the data is inaccessible. NAS data should be encrypted both in transit and at rest—in other words, when it is transmitted over the network and when it is stored in NAS devices.

2. Employ Ransomware and Virus Protection

Virus protection sometimes gets a bad rap. Yes, it’s a dated, reactive technology that has been proven to be fallible, but it’s still a valuable baseline security measure—think of it like closing and locking your front door and leaving a light on to make it look like someone is in the house. Virus protection still catches a large portion of existing malware, and antivirus (AV) vendors update their virus signatures regularly.

Ransomware protection has also become an essential element of NAS security. Newer NAS systems include software designed to detect emerging ransomware attacks, alert IT, and take steps to prevent incursions.

3. Practice Good Backup and Restore

Like AV software, backup doesn’t get the attention it deserves. It’s a tried and true method of safeguarding the enterprise, and all NAS devices and files should be regularly backed up on a timeline that reflects their value to the organization.

Even organizations with good backup practices inadvertently leave files out, however. For example, if IT adds a few new NAS devices, the backup administrator may not know about them and might subsequently leave them off the backup roster. Make sure all NAS data is backed up, and test recovery routines frequently to identify gaps to close.

4. Implement Immutability

Immutable files cannot be edited, changed, overwritten, or deleted. A smart approach for sensitive data contained in NAS devices is to make such files immutable. Locking down files in this way can also prevent them from being encrypted by cybercriminals and used as part of a ransomware attack.

5. Deploy Snapshots

Snapshots make it possible to restore a NAS system to an earlier point in time—before an error, attack, or system failure occurred, for example. When combined with immutability, snapshots can help provide a real safeguard against attack. Even if a breach occurs, the snapshot allows IT to roll the NAS back to an earlier version. They’re also far faster than backups when it comes to recovery, though rather than a replacement, they should be considered as a complement to backups.

6. Use Replication

Replication—essentially, making copies of data—is a good way to ensure the availability of NAS data. Synchronous replication is done in real-time, and is more expensive—as such, it should be reserved for mission-critical NAS data. Asynchronous replication can be used for everything else, as it is not done in real time and is much more affordable to run.

Top NAS Security Tools

With security a major concern for enterprise data, the market is increasingly full of tools designed to provide safeguards. Here are a few popular devices and tools:

• StoneFly Super Scale Out (SSO) NAS. These NAS devices include military-grade data protection and security features that are automated and proofed against malware and ransomware. 
• NetApp Ransomware Protection. NetApp’s solutions encompass several ransomware protection tools to protect, detect, and recover data by blocking cybersecurity risks and preventing downtime, and come with a guarantee of data recovery.
• Dell PowerScale. This solution uses the PowerScale OneFS file storage platform to store, protect, and manage NAS data with all-flash nodes for performance; it also secures data with federal-grade security. 
• IBM Security Guardium. This scalable data security platform protects sensitive and regulated data across multiple cloud environments, and manages compliance obligations, encrypting and monitoring what’s important to reduce risk.
• Continuity StoreGuard. Continuity’s solution scans, detects, and fixes security misconfigurations and vulnerabilities across hundreds of storage and backup devices, including NAS.

Benefits Of Securing Your NAS

Preventing incursions and breaches are the obvious benefits of securing NAS environments, but they’re not the only ones:

• Automated discovery. NAS security tools make it possible to know where all NAS devices and NAS data resides, letting the enterprise discover, classify, and catalog structured and unstructured data residing on premises or in the cloud.
• Alerting. Security tools provide alerts about possible vulnerabilities, unpatched systems, configuration issues, and other issues; data is actively monitored instead of sitting in a NAS box.
• Compliance. Compliance is increasingly important to enterprises, and NAS security tools provide the means to show evidence of compliance and detect out-of-compliance areas that require remediation. 
• Forensic investigations. When an incident occurs, NAS security tools can help investigators zero in on the point of points of incursion and how the breach spread.

Challenges of NAS Security

The challenges of NAS security boil down to the same challenges as securing the enterprise as a whole. In an organization that spans on-premises and multiple clouds—as well as multiple geographies—it can be difficult to know with certainty that all NAS systems and all NAS data is fully protected.

NAS files can be missed from backup schedules, or NAS devices in certain geographies not served by security tools. Modern NAS systems and NAS security tools provide discovery and inventorying methods to track data locations, and newer NAS devices are likely to come with security safeguards built in.

Bottom Line

NAS is very much in the firing line for ransomware and cybercriminals who find inventive ways to target vulnerabilities and infect networks. Any weakness in NAS configuration or NAS security is likely to be exploited. Those buying NAS solutions should seek out devices with built in data security features, which are increasingly available in high performance, scalable file storage systems.

Read 12 Best Practices for Enterprise Data Storage Security to learn more about how businesses are safeguarding their most important data.