OAT-008 Credential Stuffing

Credential Stuffing is an automated threat. The OWASP Automated Threat Handbook - Web Applications (pdf, print), an output of the OWASP Automated Threats to Web Applications Project, provides a fuller guide to each threat, detection methods and countermeasures. The threat identification chart helps to correctly identify the automated threat.


OWASP Automated Threat (OAT) Identity Number


Threat Event Name

Credential Stuffing

Summary Defining Characteristics

Mass log in attempts used to verify the validity of stolen username/password pairs.

Indicative Diagram

Indicative diagram for OAT-008


Lists of authentication credentials stolen from elsewhere are tested against the application’s authentication mechanisms to identify whether users have re-used the same login credentials. The stolen usernames (often email addresses) and password pairs could have been sourced directly from another application by the attacker, purchased in a criminal marketplace, or obtained from publicly available breach data dumps.

Unlike OAT-007 Credential Cracking, Credential Stuffing does not involve any brute-forcing or guessing of values; instead credentials used in other applications are being tested for validity.

Other Names and Examples

Account checker attack; Account checking; Account takeover; Account takeover attack; Login Stuffing; Password list attack; Password re-use; Stolen credentials; Use of stolen credentials

See Also


CAPEC Category / Attack Pattern IDs

  • 210 Abuse of Functionality

CWE Base / Class / Variant IDs

  • 799 Improper Control of Interaction Frequency
  • 837 Improper Enforcement of a Single, Unique Action

WASC Threat IDs

  • 21 Insufficient Anti-Automation
  • 42 Abuse of Functionality

OWASP Attack Category / Attack IDs

  • Abuse of Functionality
  • Credential Stuffing

Return to OWASP Automated Threats to Web Applications Project.