Advisory Weakness Curation

Prototype pollution in class-transformer class-transformer through 0.2.3 is vulnerable to Prototype Pollution. The 'classToPlainFromExist' function could be tricked into adding or modifying properties of 'Object.prototype' using a '__proto__' payload.

Improper Input Validation class-transformer is vulnerable to Prototype Pollution. The `classToPlainFromExist` function could be tricked into adding or modifying properties of `Object.prototype` using a `__proto__` payload.