robsware

The vulnerability is Improper Authentication

python
# vulnerable code
def login(username, password):
    if username == "admin" and password == "password123":
        return True
    else:
        return False

user_input_username = input("Enter your username: ")
user_input_password = input("Enter your password: ")

if login(user_input_username, user_input_password):
    print("Logged in successfully")
else:
    print("Invalid credentials")

python # vulnerable code def login(username, password): if username == "admin" and password == "password123": return True else: return False user_input_username = input("Enter your username: ") user_input_password = input("Enter your password: ") if login(user_input_username, user_input_password): print("Logged in successfully") else: print("Invalid credentials") In the original code, the password was being stored in plaintext, making it very easy for an attacker to obtain the password if they had access to the source code. To fix this, instead of storing the password in plaintext, we store the hash of the password (in this case, using the MD5 hashing algorithm) and compare it to the hash of the user's input. This way, even if an attacker managed to look at the source code, they would not be able to retrieve the original password, as it is not stored in the code.

python
# solution how to fix the vulnerable code
import hashlib

correct_username = "admin"
correct_password_hash = "5f4dcc3b5aa765d61d8327deb882cf99"  # hash of "password123" using md5

def login(username, password):
    password_hash = hashlib.md5(password.encode('utf-8')).hexdigest()
    if username == correct_username and correct_password_hash == password_hash:
        return True
    else:
        return False

user_input_username = input("Enter your username: ")
user_input_password = input("Enter your password: ")

if login(user_input_username, user_input_password):
    print("Logged in successfully")
else:
    print("Invalid credentials")