What is Missing Lock Check (CWE-414)?

TL;DR: Missing Lock Check (CWE-414) is a security risk where applications fail to check for locks before accessing shared resources, leading to potential data integrity and availability issues. Fix by implementing robust lock checks.

What is Missing Lock Check?

Missing Lock Check (CWE-414) is a security vulnerability where an application fails to verify the presence of a lock before performing sensitive operations on shared resources. As defined by the MITRE Corporation under CWE-414, and classified by the OWASP Foundation as not directly mapped.

Quick Summary

Missing Lock Check occurs when a product does not check for locks before accessing shared resources, leading to potential unauthorized modifications or disruptions. This can compromise data integrity and availability in multi-threaded environments. Jump to: Overview · How It Works · Business Impact · Attack Scenario · Detection · Fix · Framework-Specific Fixes · Ask AI · Checklist · FAQ · Related Vulnerabilities

Jump to: Quick Summary · Missing Lock Check Overview · How Missing Lock Check Works · Business Impact of Missing Lock Check · Missing Lock Check Attack Scenario · How to Detect Missing Lock Check · How to Fix Missing Lock Check · Framework-Specific Fixes for Missing Lock Check · How to Ask AI to Check Your Code for Missing Lock Check · Missing Lock Check Best Practices Checklist · Missing Lock Check FAQ · Vulnerabilities Related to Missing Lock Check · References · Scan Your Own Site

Missing Lock Check Overview

What: A product does not check for locks before performing sensitive operations on shared resources. Why it matters: Ensures proper synchronization of access to prevent unauthorized modifications and disruptions. Where it occurs: In multi-threaded applications or systems with concurrent resource access. Who is affected: Applications that do not implement reliable locking mechanisms. Who is NOT affected: Systems already using robust lock management techniques.

How Missing Lock Check Works

Root Cause

The root cause of Missing Lock Check is the absence of a mechanism to verify if a lock is present before performing sensitive operations on shared resources.

Attack Flow

1. An attacker identifies that a resource can be accessed without proper locking.
2. The attacker exploits this by performing unauthorized modifications or disruptions.

Prerequisites to Exploit

• Multi-threaded environment with concurrent access to shared resources.
• Absence of lock verification before accessing sensitive operations.

Vulnerable Code

def update_resource(resource_id):
    # No check for lock presence
    resource = get_resource(resource_id)
    resource.value += 10

This code does not verify if a lock is present before updating the resource, making it vulnerable to unauthorized modifications.

Secure Code

def update_resource(resource_id):
    with acquire_lock(resource_id) as lock:
        if lock.is_acquired():
            resource = get_resource(resource_id)
            resource.value += 10

The secure version ensures that a lock is acquired before performing any sensitive operations on the shared resource.

Business Impact of Missing Lock Check

Integrity: Unauthorized modifications to data can lead to incorrect or inconsistent state. Availability: Disruptions in service due to concurrent access issues.

• Financial losses from downtime and recovery efforts.
• Compliance penalties for failing security audits.
• Damage to reputation from publicized breaches.

Missing Lock Check Attack Scenario

1. An attacker identifies a shared resource that is accessed without proper locking.
2. The attacker exploits this by performing unauthorized modifications or disruptions, leading to data integrity issues and service instability.

How to Detect Missing Lock Check

Manual Testing

• [ ] Review code for operations on shared resources without lock checks.
• [ ] Verify synchronization mechanisms are implemented correctly.

Automated Scanners (SAST / DAST)

Static analysis can detect missing lock checks in source code. Dynamic testing requires runtime observation to confirm the absence of locks during concurrent access.

PenScan Detection

PenScan’s scanner engines like ZAP and Nuclei can identify Missing Lock Check vulnerabilities by analyzing code patterns and resource access mechanisms.

False Positive Guidance

False positives may occur if a locking mechanism is present but not correctly utilized. Ensure that lock checks are implemented before sensitive operations to distinguish from false alarms.

How to Fix Missing Lock Check

• Implement reliable lock mechanisms.
• Verify proper synchronization of resource access in multi-threaded environments.

Framework-Specific Fixes for Missing Lock Check

Java

public synchronized void updateResource(int resourceId) {
    // Perform operation on shared resource
}

Ensure that all operations on shared resources are protected by appropriate locks or synchronization primitives.

Python/Django

def update_resource(resource_id):
    with acquire_lock(resource_id) as lock:
        if lock.is_acquired():
            # Perform operation on shared resource

Use context managers to ensure proper acquisition and release of locks before performing sensitive operations.

How to Ask AI to Check Your Code for Missing Lock Check

Missing Lock Check Best Practices Checklist

✅ Implement reliable lock mechanisms. ✅ Verify proper synchronization of resource access in multi-threaded environments.

Missing Lock Check FAQ

How does Missing Lock Check occur in an application?

Missing Lock Check occurs when a product fails to verify the presence of a lock before performing sensitive operations on a resource.

Why is Missing Lock Check considered a security risk?

It can lead to unauthorized modifications or disruptions, compromising data integrity and availability.

Can you provide an example of vulnerable code for Missing Lock Check?

A function that accesses a shared resource without checking if the lock is acquired first demonstrates this vulnerability.

What are some best practices to prevent Missing Lock Check?

Always implement reliable locking mechanisms and ensure proper synchronization of access to shared resources.

How can developers mitigate Missing Lock Check in their code?

Developers should verify that all sensitive operations on shared resources are protected by appropriate locks or synchronization primitives.

What is the relationship between CWE-414 and other security weaknesses?

Missing Lock Check (CWE-414) is a specific case of Improper Locking (CWE-667).

How can I use AI to check for Missing Lock Check in my code?

Review your code with an AI assistant by pasting the relevant section and asking it to identify potential CWE-414 issues.

Vulnerabilities Related to Missing Lock Check

| CWE | Name | Relationship | |—|—|—| | CWE-667 | Improper Locking | ChildOf |

References

• MITRE
• CAPEC
• NVD

Scan Your Own Site

Manual code review catches what you know to look for. An automated scan catches what you didn’t. Scan your own website using PenScan to find Missing Lock Check and other risks before an attacker does.