Weakness · High
CWE-645: Overly Restrictive Account Lockout Mechanism
What it is
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.
- Severity (our rating)
- High
- Likelihood of exploit
- High
- Introduced during
- Architecture and Design
- Exploited in the wild
- 1 known exploited CVE
In more detail
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.
What an attacker can do
- DoS: Resource Consumption (Other) (Availability)
How to prevent it
Architecture and Design
- Implement more intelligent password throttling mechanisms such as those which take IP address into account, in addition to the login name.
- Implement a lockout timeout that grows as the number of incorrect login attempts goes up, eventually resulting in a complete lockout.
- Consider alternatives to account lockout that would still be effective against password brute force attacks, such as presenting the user machine with a puzzle to solve (makes it do some computation).
Exploited in the wild: 1 CVE
Vulnerabilities caused by CWE-645 that attackers have used, from CISA's Known Exploited Vulnerabilities catalog, newest first.
H2 Security
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Start freeSource: MITRE Common Weakness Enumeration, CWE version 4.19.1. CWE is a trademark of The MITRE Corporation.