A host header injection vulnerability exists in the NPM package of perfood/couch-auth <= 0.21.2. By sending a specially crafted host header in the email change confirmation request, it is possible to trigger a SSTI which can be leveraged to run limited commands or leak server-side information
The product constructs all or part of a command, data structure, or record using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify how it is parsed or interpreted when it is sent to a downstream component.