Credential Stuffing vs Password Spraying

Introduction

Credential stuffing and password spraying pose significant threats to account security. While both methods attempt unauthorised access, they use different approaches. This article examines each attack type and outlines key differences.

What is Credential Stuffing?

Credential stuffing uses stolen username and password pairs to gain unauthorised access to user accounts. Attackers obtain large lists of credentials from data breaches and test them across multiple websites and services. This exploits users' tendency to reuse passwords.

The process involves:

Obtaining stolen credentials from the dark web or data breaches
Using automated tools to input credentials on target sites
Testing thousands or millions of combinations rapidly
Gaining access to accounts where credentials match

Credential stuffing relies on users reusing passwords across multiple accounts. Even a small percentage of matches can compromise many accounts.

Bot management solutions can detect and block the automated requests used in credential stuffing attacks.

What is Password Spraying?

Password spraying targets many accounts using a small set of common passwords. Rather than using specific username-password pairs, attackers try a few popular passwords against numerous accounts.

The method involves:

Selecting a list of common passwords (e.g. "Password123", "Welcome2024")
Attempting these passwords against many usernames or email addresses
Spacing out attempts to avoid lockouts
Compromising accounts using weak, common passwords

Password spraying circumvents typical lockout protections by limiting attempts per account. It exploits the human tendency to choose weak, predictable passwords.

Advanced rate limiting can help mitigate password spraying by restricting login attempts across IP addresses and devices.

Key Differences

Credential stuffing and password spraying differ in several ways:

Data required: Credential stuffing needs specific username-password pairs. Password spraying only requires usernames/emails.
Number of passwords: Credential stuffing tests many passwords. Password spraying uses few common passwords.
Target accounts: Credential stuffing targets accounts on multiple services. Password spraying focuses on many accounts within one service.
Detection difficulty: Credential stuffing generates high volumes of traffic. Password spraying can blend with normal login attempts.
Success rate: Credential stuffing succeeds more often but requires more resources. Password spraying has a lower success rate but requires less effort.

Prevention Measures

Organisations can implement several measures to protect against these attacks:

Enforce strong password policies
Implement multi-factor authentication
Use breached credentials checks
Deploy bot detection and mitigation tools
Utilise IP intelligence to identify suspicious traffic
Implement account lockout policies
Monitor for unusual login patterns
Educate users on password security
Use residential proxy detection to identify attack traffic

Users should:

Use unique passwords for each account
Enable multi-factor authentication when available
Check if their credentials have been compromised
Use a password manager to generate and store strong passwords

By understanding the differences between credential stuffing and password spraying, organisations can implement targeted defences against these account takeover attempts.