C++ char* problem: changing the input changes the entire linked list

//main.cpp

#include "code.h"

1 int main (void){
2
3	List *obj = new List();
4	char *input = new char[20];
5	int option = 0;
6	bool caseBool = true;
7
8	while (caseBool != false){
9
10		cout << "1. Enter contact: " << endl;
11		cout << "2. Print Contacts" << endl;
12		cout << "3. Exit" << endl;
13		cin >> option;
14
15		system ("cls");
16
17		if (option == 1){
18
19			cout << "Enter Contact Name: ";
20			cin >> input; <--------------------This line changes the contents of the whole list
21			obj->insertFront(input);           to the second value I enter.
22		}
23		else if (option == 2){
24
25			obj->print();
26			system ("pause");
27		}
		else if (option == 3){

			caseBool = false;
		}
		else{

			system ("cls");
			cout << "Invalid input" << endl;
			system ("pause");
		}

		system ("cls");
	}
	
	return 0;
}

//code.cpp

#include "code.h"

void List::insertFront(char* data){

	ListNode *newNode = new ListNode(data);

	if (isEmpty()){

		newNode->nextPtr = NULL;
		firstPtr = newNode;
	}
	else{

		newNode->nextPtr = firstPtr;
		firstPtr = newNode;
	}
}

void List::print() const{

	ListNode *tempPtr = firstPtr;

	while (tempPtr != NULL){

		cout << tempPtr->data << endl;
		tempPtr = tempPtr->nextPtr;
	}
}

bool List::isEmpty(){

	bool empty = false;

	if (firstPtr == NULL){

		return true;
	}

	return empty;
}

// code.h

#pragma once

#include <iostream>
using namespace std;

class ListNode{

	friend class List;

public:

	//explicit ListNode(int initialVal) 
		//: data(initialVal){}
	explicit ListNode(char* name) : data(name){};

	//ListNode (const ListNode &rhs);

	char *getData()const{
	
		return data;

	};

	void writeData(char* input){

		data = input;
	}

private:

	char *data;

	ListNode *nextPtr;
};

class List{

public:
	List(){
		
		firstPtr = NULL;

	};
	~List(){
	
		delete firstPtr;
	};

	void insertFront (char *data);
	bool isEmpty();
	void print() const;

private:

	ListNode *firstPtr;

};