When it comes to patching and updating software vulnerabilities, operating systems and web browsers seem to get all the love.
But in reality, vulnerabilities in those two types of software usually account for a minority of the publicly disclosed vulnerabilities published in the National Vulnerability Database (NVD), the U.S. government’s repository of standards-based vulnerability management data.
Where are the rest of the vulnerabilities? The majority are in applications (i.e. software that doesn’t ship as part of operating systems or browsers), and unless you’re spending time protecting those too, your application layer could be a big chink in your IT armor. CIOs, CISOs and their security teams need to focus on assessing and patching known vulnerabilities in all business apps, or they could in fact be missing the bulk of the vulnerabilities that exist in their environments.
But separating core OS applications and web browsers from the rest of the application layer can be a bit murky. Comparing vulnerabilities that affect a computer’s operating system to vulnerabilities that affect other components, such as applications and utilities, requires a determination of whether the affected component is part of an operating system. This determination is not always simple and straightforward, given the componentized nature of modern operating systems.
For example, some programs (like photo editors) ship by default with operating system software, but can also be downloaded from the software vendor’s website and installed individually. Linux distributions, in particular, are often assembled from components developed by different teams, many of which provide crucial operating functions such as a graphical user interface (GUI) or Internet browsing.
To help companies navigate this issue and facilitate analysis of operating system and browser vulnerabilities, the Microsoft Security Intelligence Report distinguishes among four different kinds:
- Core operating system vulnerabilities are those with at least one operating system platform enumeration in the NVD that do not also have any application platform enumerations.
- Operating system application vulnerabilities are those with at least one OS platform enumeration and at least one application platform enumeration listed in the NVD, except for browsers.
- Browser vulnerabilities are those that affect components defined as part of a web browser, including web browsers such as Internet Explorer and Apple’s Safari that ship with operating systems, along with third-party browsers such as Mozilla Firefox and Google Chrome.
- Other application vulnerabilities are those with at least one application platform enumeration in the NVD that do not have any OS enumerations, except for browsers.
With those distinctions in mind, the latest SIR reports that disclosures of vulnerabilities in applications decreased in the second half of 2015, but remained the most common type of vulnerability during the period, accounting for 44.2 percent of all disclosures — a big number that any organization’s security team should be paying attention to.
Meanwhile, the other categories are important too. Core operating system vulnerability disclosures increased dramatically from the first half of the year, moving into second place at 24.5 percent. Operating system application disclosures decreased slightly to account for 18.6 percent, while browser disclosures increased by more than a third to account for 12.8 percent.
The key to keeping any organization safe is to stay on top of all disclosures, no matter which part of the stack they belong in. To stay on top of possible vulnerabilities across your software stack, take a look at our latest Security Intelligence Report and the information available through the NVD. And for a high-level look at the top 10 trends and stats that matter most to security professionals right now, be sure and download our 2016 Trends in Cybersecurity e-book.