Improperly Controlled Modification of Object Prototype Attributes (Prototype Pollution) vulnerability in Mozilla Convict.
This allows an attacker to inject attributes that are used in other components, or to 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 its 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.
This issue affects Convict: before 6.2.4.
The product receives input from an upstream component that specifies attributes that are to be initialized or updated in an object, but it does not properly control modifications of attributes of the object prototype.