The improper storage of passwords poses a significant security risk to software applications. This vulnerability arises when passwords are stored in plain-text or with a fast hashing algorithm. To exploit this vulnerability, an attacker typically requires access to the stored passwords.
Attackers who would get access to the stored passwords could reuse them without further attacks or with little additional effort. Obtaining the clear-text passwords, they could then gain unauthorized access to user accounts, potentially leading to various malicious activities.
=== What is the potential impact?
Plain-text or weakly hashed password storage poses a significant security risk to software applications.
==== Unauthorized Access
When passwords are stored in plain-text or with weak hashing algorithms, an attacker who gains access to the password database can easily retrieve and use the passwords to gain unauthorized access to user accounts. This can lead to various malicious activities, such as unauthorized data access, identity theft, or even financial fraud.
==== Credential Reuse
Many users tend to reuse passwords across multiple platforms. If an attacker obtains plain-text or weakly hashed passwords, they can potentially use these credentials to gain unauthorized access to other accounts held by the same user. This can have far-reaching consequences, as sensitive personal information or critical systems may be compromised.
==== Regulatory Compliance
Many industries and jurisdictions have specific regulations and standards to protect user data and ensure its confidentiality. Storing passwords in plain-text or with weak hashing algorithms can lead to non-compliance with these regulations, potentially resulting in legal consequences, financial penalties, and damage to the reputation of the software application and its developers.
== How to fix it in Spring
A user password should never be stored in clear text. Instead, a hash should be produced from it using a secure algorithm:
* not vulnerable to brute force attacks.
* not vulnerable to first preimage or second preimage attacks: If a hash is leaked, it should be difficut to find a password produding this same hash. It should also be difficult to find a password that has the same hash than another password.
* and a salt should be added to the password to lower the risk of rainbow table attacks (see rule S2053).
While considered strong for some use cases, some algorithms, like SHA-family functions, are too fast to compute and therefore susceptible to brute force attacks, especially with attack-dedicated hardware. Modern, slow, password hashing algorithms such as bcrypt, PBKDF2 or argon2 are recommended.
The ``BCryptPasswordEncoder`` is a password hashing function in Java that is designed to be secure and resistant to various types of attacks, including brute-force and rainbow table attacks. It is slow, adaptative, and automatically implements a salt.
== Resources
=== Documentation
* Spring Framework Security Documentation - https://docs.spring.io/spring-security/site/docs/current/api/org/springframework/security/crypto/bcrypt/BCryptPasswordEncoder.html[Class BCryptPasswordEncoder]
