Credential Stuffing vs. Password Spraying

Estimated reading time: 2 minutes

Both credential stuffing and password spraying are brute-force attack techniques used to gain unauthorized access to accounts, but they differ in execution and intent.

1. Credential Stuffing

• Attack Method:
  • Uses previously leaked or stolen username-password pairs (often from data breaches) to attempt logins on other services.
  • Assumes that users reuse credentials across multiple platforms.
• Attack Pattern:
  • The attacker submits different username-password pairs for each login attempt.
  • Example:
    user1@example.com : password123
user2@example.com : qwerty123
user3@example.com : letmein
• Detection Avoidance:
  • Difficult to detect because each login attempt uses valid credentials.
  • Can bypass rate-limiting since each username has only one attempt before moving to the next.
• Common Targets:
  • Websites, cloud services, online banking, e-commerce platforms.
• Countermeasures:
  • Multi-Factor Authentication (MFA).
  • Credential monitoring (checking for leaked credentials).
  • Login anomaly detection (geo-location, device fingerprinting).

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2. Password Spraying

• Attack Method:
  • Tries a small number of common passwords (e.g., “Password123”, “Welcome1”) across many different accounts.
  • Avoids account lockout by spreading attempts across multiple accounts.
• Attack Pattern:
  • The attacker picks one password and tries it against multiple accounts before moving to another password.
  • Example:
    user1@example.com : Password123
user2@example.com : Password123
user3@example.com : Password123
    
    
  • Then, if unsuccessful:
    user1@example.com : Welcome1
user2@example.com : Welcome1
user3@example.com : Welcome1
    
    
• Detection Avoidance:
  • Slower approach prevents account lockouts due to too many failed login attempts.
  • Harder to detect since individual accounts do not show excessive failed logins.
• Common Targets:
  • Corporate environments (Active Directory, Office 365, VPNs, web apps).
• Countermeasures:
  • Enforcing strong, unique passwords.
  • Monitoring for failed login patterns across multiple accounts.
  • Implementing account lockout policies with gradual cooldown periods.

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Key Differences

Aspect	Credential Stuffing	Password Spraying
Relies on	Stolen username-password pairs	Guessing common passwords
Attack Type	One attempt per user (valid stolen credentials)	One password across many users
Lockout Avoidance	Avoids detection using real credentials	Avoids detection by low-volume attempts
Common Targets	Any online service with login authentication	Corporate systems, enterprise apps
Countermeasures	MFA, breach monitoring, anomaly detection	Strong passwords, monitoring failed login patterns

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