The Truth About Vulnerability Scanners

Excerpted from "Scanning Reality: Limits of Automated Vulnerability Scanners," a new report posted today in Dark Reading's Vulnerability Management Tech Center.

In some enterprises, the term "vulnerability management" begins and ends with scanning tools. For these enterprises, improving vulnerability management simply means bringing in more scanners to ensure a broad view.

But are network-based vulnerability scanners and Web application scanning tools enough to ensure that your organization will identify and remediate its security vulnerabilities -- before they are exploited by the bad guys? We submit that most IT organizations have a limited understanding of what these tools can do -- and where they fall short.

There are three key limitations of vulnerability scanners. Some of the risks around these problems can be mitigated by incorporating additional technologies into your vulnerability management program, while others are beyond the scope of any automated technology.

Whatever mitigation strategy is used to fill the gap left by these scanners, the first step is to understand their shortcomings.

The first problem area is authentication. Network-based vulnerability scanners are imperfect tools at best. Even when they are properly configured, they detect only vulnerabilities for which they have signatures. While anonymous (unauthenticated) scanning can provide some benefit, failure to leverage authenticated scanning dramatically reduces scanner effectiveness.

A second key problem is the scanner's inability to work with custom applications. CVE-based, known vulnerabilities are only a small subset of most organizations' overall attack surfaces. Security checks may exist for the most popular applications and operating systems hosted within your network, but what about the custom applications you have written in-house or outsourced to third parties? There are no CVEs for custom apps.

Finally, most vulnerability scanning tools can identify points of weakness, but they can't anticipate complex attack schemes. While vulnerability scanners typically identify and report on issues that can be utilized as the initial point of entry, they are limited in identifying the complex avenues an attacker could take to compromise your network.

Automated vulnerability scanners play a critical role in helping you manage and understand the security risks that may exist within your environment. However, like any tool, the capabilities and results of these tools need to be fully understood and their limitations noted.

To get details on these key limitations, and some recommendations on how to address them, download the full report.

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