GHSA-jjf5-wx3j-3fv7 Prototype Pollution in convict

• npm convict: < 6.2.3 → fixed in 6.2.3

This affects the package convict before 6.2.3. This is a bypass of CVE-2022-22143. The fix introduced, relies on the startsWith method and does not prevent the vulnerability: before splitting the path, it checks if it starts with __proto__ or this.constructor.prototype. To bypass this check it's possible to prepend the dangerous paths with any string value followed by a dot, like for example foo.__proto__ or foo.this.constructor.prototype.