How secure are open source libraries?

Seven in 10 applications have a security flaw in an open source library, highlighting how use of open source can introduce flaws, increase risk, and add to security debt, a Veracode research reveals.

Nearly all modern applications, including those sold commercially, are built using some open source components. A single flaw in one library can cascade to all applications that leverage that code.

According to Chris Eng, Chief Research Officer at Veracode, “Open source software has a surprising variety of flaws. An application’s attack surface is not limited to its own code and the code of explicitly included libraries, because those libraries have their own dependencies.

“In reality, developers are introducing much more code, but if they are aware and apply fixes appropriately, they can reduce risk exposure.”

Open source libraries are ubiquitous and pose risks

• The most commonly included libraries are present in over 75% of applications for each language.
• Most flawed libraries end up in code indirectly: 47% of those flawed libraries in applications are transitive – in other words, not pulled in directly by developers, but are being pulled in by upstream libraries. Library-introduced flaws in most applications can be fixed with only a minor version update; major library upgrades are not usually required.
• Not all libraries have Common Vulnerabilities and Exposures (CVEs) – this means developers can’t rely only on CVEs to understand library flaws. For example, more than 61% of flawed libraries in JavaScript contain vulnerabilities without corresponding CVEs.

Language makes a difference

• Some language ecosystems tend to pull in many more transitive dependencies than others. In more than 80% of JavaScript, Ruby, and PHP applications, the majority of libraries are transitive dependencies.
• Language selection makes a difference both in terms of the size of the ecosystem and in the prevalence of flaws in those ecosystems. Including any given PHP library has a greater than 50% chance of bringing a security flaw along with it.
• Among the OWASP Top Ten flaws, weaknesses around access control are the most common, representing over 25% of all flaws. Cross-Site Scripting is the most common vulnerability category found in open source libraries – found in 30% of libraries – followed by insecure deserialization (23.5%) and broken access control (20.3%).