Understanding Application Whitelisting: A Definition from TechTarget

Application allowlisting, once called application whitelisting, is all about creating a list of approved software that can run on a computer system. This process helps shield computers and networks from dangerous applications and cybersecurity threats, like ransomware and malware.

An allowlist is essentially a directory of approved entities. In cybersecurity, it works best in environments where systems have a stable workload. The National Institute of Standards and Technology recommends using allowlisting in high-risk situations, especially where security matters more than software usability. For more adaptability, an allowlist can include trusted components, such as software libraries and plugins.

So, how does application allowlisting function? First, you gather a list of approved applications and IT components. This list can be part of the operating system or supplied by a third-party vendor. The simplest approach involves system administrators defining attributes associated with allowed applications, like file names or sizes. Allowlisting takes a proactive security stance, blocking anything not on the approved list.

For example, every Windows 10 and 11 system includes Microsoft Windows Defender Application Control, now known as App Control for Windows. This tool allows administrators to determine which users can run specific applications. It controls application execution based on parameters like file paths and publisher identities, limiting access and preventing unwanted software installations.

Application allowlisting plays a crucial role in protecting computers and networks from various malware types.

Advantages of application allowlisting:

1. Strengthened Security: It offers better protection against ransomware and malware by thoroughly inspecting files. Unlike traditional antivirus, which relies on known signatures, allowlisting doesn’t let any executable run unless explicitly allowed by an administrator.

2. User Access Tracking: Depending on the tool’s reporting abilities, allowlisting can reveal risky user behaviors and access to sensitive data. Reports can detail unauthorized installation attempts and detected malware.

3. License Compliance: By restricting unauthorized applications, allowlisting helps avoid situations where an organization might face licensing violations due to unaware usage.

4. Reduced Help Desk Costs: IT can manage which applications users can access, decreasing the chances of software conflicts and ensuring stable application versions.

Challenges of application allowlisting:

1. Imitation Risks: Attackers can replace allowlisted applications with malicious ones. To counter this, allowlisting tools should use cryptographic hashes and digital signatures linked to developers.

2. Maintenance Complexity: As organizations frequently add applications, the allowlist must be updated accordingly, complicating installation and activation processes.

3. Update Interference: If the allowlist isn’t kept current with software updates, users may be unable to access new features or security patches.

When comparing application allowlisting to blocklisting, the key difference lies in the approach. Allowlisting is more restrictive; only approved applications can run. While there’s debate about which method is superior, those in favor of allowlisting argue it offers better protection against malicious software.

Application control and allowlisting often get confused, but they aren’t the same. Application control monitors applications during installation but has limitations; it doesn’t inspect the files of installed programs, which leaves room for cyber threats.

Best practices for implementing application allowlisting:

1. Inventory Applications: Start by compiling a complete list of applications to include in the allowlist.

2. Identify Allowlisted Applications: Instead of using specific folders or file names— which can lead to vulnerabilities— opt for publisher signatures or file hashes for more security.

3. Ensure Robust Endpoint Security: Strengthen endpoint security by identifying applications through reliable methods.

4. Plan for Long-Term Management: Have a strategy for consistently updating the allowlist as new applications and upgrades are adopted.

5. Combine Allowlisting with Patch Management: Ensure application and patch management processes work together to prevent access issues following updates. Consider using vendor digital signatures to streamline this process.

Staying on top of software patches reduces security risks and service interruptions. Understanding patch management features can significantly benefit your organization in maintaining a secure environment.