COMMON ATTACK PATTERN ENUMERATION AND CLASSIFICATIONLive MITRE record

CAPEC-2

Inducing Account Lockout

An attacker leverages the security functionality of the system aimed at thwarting potential attacks to launch a denial of service attack against a legitimate system user. Many systems, for instance, implement a password throttling mechanism that locks an account after a certain number of incorrect log in attempts. An attacker can leverage this throttling mechanism to lock a legitimate user out of their own account. The weakness that is being leveraged by an attacker is the very security feature that has been put in place to counteract attacks.

Abstraction

Standard

Typical severity

Medium

Likelihood of attack

High

Understand the attack

What is this attack pattern?

An attacker leverages the security functionality of the system aimed at thwarting potential attacks to launch a denial of service attack against a legitimate system user. Many systems, for instance, implement a password throttling mechanism that locks an account after a certain number of incorrect log in attempts. An attacker can leverage this throttling mechanism to lock a legitimate user out of their own account. The weakness that is being leveraged by an attacker is the very security feature that has been put in place to counteract attacks.

Execution flow

How does the attack proceed, step by step?

1

Experiment

Investigate account lockout behavior of system

Investigate the security features present in the system that may trigger an account lockout

Techniques used

  • Analyze system documentation to find list of events that could potentially cause account lockout
  • Obtain user account in system and attempt to lock it out by sending malformed or incorrect data repeatedly
  • Determine another user's login ID, and attempt to brute force the password (or other credentials) for it a predetermined number of times, or until the system provides an indication that the account is locked out.

Obtain list of user accounts to lock out

Generate a list of valid user accounts to lock out

Techniques used

  • Obtain list of authorized users using another attack pattern, such as SQL Injection.
  • Attempt to create accounts if possible; system should indicate if a user ID is already taken.
  • Attempt to brute force user IDs if system reveals whether a given user ID is valid or not upon failed login attempts.
2

Exploit

Lock Out Accounts

Perform lockout procedure for all accounts that the attacker wants to lock out.

Techniques used

  • For each user ID to be locked out, perform the lockout procedure discovered in the first step.

Requirements

What does the attack require?

Prerequisites

  • The system has a lockout mechanism.
  • An attacker must be able to reproduce behavior that would result in an account being locked.

Skills required

  • Low: No programming skills or computer knowledge is needed. An attacker can easily use this attack pattern following the Execution Flow above.

Resources required

  • Computer with access to the login portion of the target system

Impact

What does a successful attack lead to?

Resource Consumption

Affected scopes: Availability

Defence

How is it prevented and mitigated?

1
Implement intelligent password throttling mechanisms such as those which take IP address into account, in addition to the login name.
2
When implementing security features, consider how they can be misused and made to turn on themselves.

Real world

MITRE example instances

Example instance 1Detail
A famous example of this type an attack 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.
CAPEC-2: Inducing Account Lockout — DayBreach Saldırı Sözlüğü · DayBreach