Coana uses a static analysis known as a control-flow analysis to build a model of the analyzed program. This model, commonly known as a call graph, contains information about how the execution flows through the program. It allows us to answer questions like ‘from this specific place in my program to what other places in the program can the program execution go‘, where ‘this specific place’ could be any line in the analyzed program. Based on the call graph, Coana is able to tell which parts of the code are dead (unreachable) and which parts or live (reachable). You can learn more about how the static analysis works in the post What is SCA with reachability?

The reachability analysis is designed to over-approximate the actual runtime reachability of vulnerabilities. By over-approximating, the analysis will lean toward marking a vulnerability as reachable whenever it’s in doubt. By taking this approach, Coana allows you to safely ignore unreachable vulnerabilities without compromising on any real security.

At Coana, we have a dedicated security team that works on answering exactly that question. Whenever a new vulnerability is discovered, the security team initiates a thorough investigation of all the various resources related to the vulnerability. The team typically installs the affected package, reads the documentation, and builds a detailed understanding of how the package works. Once the functions, methods, properties, etc., responsible for the vulnerability have been identified, the team writes a specification that captures exactly these parts of the package. This specification is then used by the static analysis when it performs a reachability analysis on your code.

As a bonus, the team also writes an informal, human-readable version of this specification, which users of Coana can use to better understand the vulnerability.

We recommend running Coana on a regular basis in your CI/CD environment. Check our documentation to learn more about how Coana is setup.