convict vulnerable to Prototype Pollution
### Impact
* An attacker can inject attributes that are used in other components
* An attacker can override existing attributes with ones that have incompatible type, which may lead to a crash.
The main use case of Convict is for handling server-side configurations written by the admins owning the servers, and not random users. So it's unlikely that an admin would deliberately sabotage their own server. Still a situation can happen where an admin not knowledgeable about JavaScript could be tricked by an attacker into writing the malicious JavaScript code into some config files.
### Patches
The problem is patched in `convict@6.2.4`. Users should upgrade to `convict@6.2.4`.
### Workarounds
No way for users to fix or remediate the vulnerability without upgrading
### References
https://github.com/mozilla/node-convict/issues/410