CWE-645: Overly Restrictive Account Lockout Mechanism
Description
The product contains an account lockout protection mechanism, but the mechanism is too restrictive and can be triggered too easily, which allows attackers to deny service to legitimate users by causing their accounts to be locked out.
Submission Date :
Jan. 30, 2008, midnight
Modification Date :
2023-06-29 00:00:00+00:00
Organization :
Cigital
Extended Description
Account lockout is a security feature often present in applications as a countermeasure to the brute force attack on the password based authentication mechanism of the system. After a certain number of failed login attempts, the users' account may be disabled for a certain period of time or until it is unlocked by an administrator. Other security events may also possibly trigger account lockout. However, an attacker may use this very security feature to deny service to legitimate system users. It is therefore important to ensure that the account lockout security mechanism is not overly restrictive.
Example - 1
A famous example of this type of weakness being exploited is the eBay attack. eBay always displays the user id of the highest bidder. In the final minutes of the auction, one of the bidders could try to log in as the highest bidder three times. After three incorrect log in attempts, eBay password throttling would kick in and lock out the highest bidder's account for some time. An attacker could then make their own bid and their victim would not have a chance to place the counter bid because they would be locked out. Thus an attacker could win the auction.
Related Weaknesses
This table shows the weaknesses and high level categories that are related to this weakness. These relationships are defined to give an overview of the different insight to similar items that may exist at higher and lower levels of abstraction.
Visit http://cwe.mitre.org/ for more details.