Architecture with Number of Horizontal Layers Outside of Expected Range

The product's architecture contains too many - or too few - horizontal layers.

This issue makes it more difficult to maintain the product, which indirectly affects security by making it more difficult or time-consuming to find and/or fix vulnerabilities. It also might make it easier to introduce vulnerabilities.

While the interpretation of "expected range" may vary for each product or developer, CISQ recommends a default minimum of 4 layers and maximum of 8 layers.