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.
Last updated
Overview
CAPEC-2 (Inducing Account Lockout) is a standard-level attack pattern catalogued by MITRE in the Common Attack Pattern Enumeration and Classification (CAPEC). It describes a recurring method attackers use to exploit software weaknesses.
How the attack works
The phases an attacker typically follows to carry out this attack.
- Step 1Experiment
[Investigate account lockout behavior of system] Investigate the security features present in the system that may trigger an account lockout
- 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.
- Step 2Experiment
[Obtain list of user accounts to lock out] Generate a list of valid user accounts to lock out
- 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.
- Step 3Exploit
[Lock Out Accounts] Perform lockout procedure for all accounts that the attacker wants to lock out.
- For each user ID to be locked out, perform the lockout procedure discovered in the first step.
What the attacker needs
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 skill: 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
Consequences
What a successful CAPEC-2 attack can achieve.
Resource Consumption
Affects: Availability
Denial of Service
How to mitigate it
Defenses that reduce the risk of CAPEC-2.
- Implement intelligent password throttling mechanisms such as those which take IP address into account, in addition to the login name.
- When implementing security features, consider how they can be misused and made to turn on themselves.
Examples
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.
Terminology & mappings
Mapped taxonomies
- ATTACK: Account Access Removal (1531)
Frequently asked questions
Common questions about CAPEC-2.
- What is CAPEC-2?
- 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.
- How does a Inducing Account Lockout attack work?
- It typically unfolds over 3 phases. It begins with: [Investigate account lockout behavior of system] Investigate the security features present in the system that may trigger an account lockout
- How do you prevent CAPEC-2?
- Implement intelligent password throttling mechanisms such as those which take IP address into account, in addition to the login name.
- What weaknesses does CAPEC-2 target?
- CAPEC-2 exploits 1 CWE weakness, including CWE-645 (Overly Restrictive Account Lockout Mechanism).
- How severe is CAPEC-2?
- MITRE rates CAPEC-2 as Medium severity with high likelihood of attack.
References
Attack-pattern data is sourced from the MITRE CAPEC catalog (v3.9). Weakness associations link to the corresponding CWE entries on RadicalNotion.AI.
Defend against CAPEC-2
Track the CVEs and weaknesses attackers exploit with this technique, with AI-written analysis and remediation guidance.