What is Permission Race Condition During (CWE-689)?

TL;DR: Permission Race Condition During Resource Copy (CWE-689) occurs when an application copies resources without setting proper permissions, exposing them to unauthorized access. Fix by applying permissions immediately upon copying.

What is Permission Race Condition During Resource Copy?

Permission Race Condition During Resource Copy (CWE-689) is a type of race condition vulnerability defined by the MITRE Corporation under CWE-689. It occurs when an application copies or clones resources without immediately setting proper permissions, leaving them exposed to unauthorized access during this brief window.

Quick Summary

A permission race condition can expose sensitive data and allow unauthorized modifications during the period when permissions are not set. This vulnerability is critical as it undermines security measures that rely on timely enforcement of access controls.

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

Permission Race Condition During Resource Copy Overview

What

Permission Race Condition During Resource Copy is a race condition where an application copies resources without setting proper permissions immediately.

Why it matters

This vulnerability exposes sensitive data and allows unauthorized modifications during the brief period when permissions are not set, leading to significant security risks.

Where it occurs

It can occur in any application that copies or clones resources without immediately enforcing access controls.

Who is affected

Developers and organizations using applications that handle resource copying without proper permission handling.

Who is NOT affected

Applications that enforce strict immediate permissions upon resource creation or modification.

How Permission Race Condition During Resource Copy Works

Root Cause

The root cause lies in the delayed enforcement of permissions after a resource copy, leaving it exposed to unauthorized access during this window.

Attack Flow

1. An attacker identifies a resource being copied.
2. The attacker exploits the unprotected state by modifying or accessing the resource before permissions are set.

Prerequisites to Exploit

• Resource copying without immediate permission enforcement.
• Access to the system during the brief period when permissions are not enforced.

Vulnerable Code

def copy_resource(src, dest):
    shutil.copy2(src, dest)

This code copies a file from src to dest, but does not enforce proper permissions immediately after copying.

Secure Code

import os

def copy_resource_securely(src, dest):
    shutil.copy2(src, dest)
    os.chmod(dest, 0o644)  # Set the correct permission immediately.

The secure version ensures that permissions are set immediately upon resource creation to prevent unauthorized access.

Business Impact of Permission Race Condition During Resource Copy

Confidentiality

• Data exposure during unprotected state.
• Unauthorized access to sensitive files.

Integrity

• Unauthorized modification of critical resources.

Availability

• Potential disruption if the resource is essential for system operation.

Real-world business consequences:

• Financial loss from compromised data integrity and unauthorized modifications.
• Compliance penalties due to non-compliance with security standards.
• Damage to reputation and customer trust following a breach.

Permission Race Condition During Resource Copy Attack Scenario

1. An attacker identifies an ongoing resource copy process.
2. The attacker exploits the unprotected state by modifying or accessing the resource before proper permissions are set.
3. Unauthorized access leads to data exposure or modification, compromising system integrity.
4. The attacker leverages the compromised resource for further malicious activities.

How to Detect Permission Race Condition During Resource Copy

Manual Testing

• Review code for delayed permission enforcement after resource copying.
• Verify that immediate permission setting is implemented upon resource creation.

Automated Scanners (SAST/DAST)

Static analysis can identify instances where permissions are not set immediately. Dynamic testing can simulate attacks during the unprotected window to validate vulnerabilities.

PenScan Detection

PenScan uses ZAP, Nuclei, Wapiti, Nikto, SSLyze, and Dalfox to detect permission race conditions during resource copying.

False Positive Guidance

A false positive occurs if a scanner flags code that enforces permissions immediately after the copy operation. Ensure that the identified window of exposure is genuine before confirming as a vulnerability.

How to Fix Permission Race Condition During Resource Copy

• Enforce proper permissions immediately upon resource creation.
• Use secure coding practices to ensure immediate enforcement of access controls.
• Implement robust validation and authorization checks during resource copying operations.

Framework-Specific Fixes for Permission Race Condition During Resource Copy

import os

def copy_resource_securely(src, dest):
    shutil.copy2(src, dest)
    os.chmod(dest, 0o644)  # Set the correct permission immediately.

This Python example ensures that permissions are set immediately upon resource creation to prevent unauthorized access.

How to Ask AI to Check Your Code for Permission Race Condition During Resource Copy

Permission Race Condition During Resource Copy Best Practices Checklist

✅ Enforce proper permissions immediately upon resource creation. ✅ Use secure coding practices to ensure immediate enforcement of access controls. ✅ Implement robust validation and authorization checks during resource copying operations. ✅ Regularly review and update security policies for resource management. ✅ Conduct thorough testing to validate the effectiveness of permission enforcement mechanisms.

Permission Race Condition During Resource Copy FAQ

How does a permission race condition during resource copy occur?

A permission race condition occurs when an application copies or clones a resource and temporarily leaves it exposed to unauthorized access while the permissions are being set.

What is the impact of a permission race condition during resource copy on data integrity?

It can lead to unauthorized modification of critical resources, compromising data integrity by allowing attackers to alter sensitive files before proper access controls are enforced.

How do developers prevent permission race conditions when copying or cloning resources in their applications?

Developers should ensure that permissions and access controls are set immediately after a resource is copied, without leaving it exposed during the transition period.

Can you provide an example of vulnerable code for a permission race condition during resource copy?

Vulnerable code might involve copying a file and then setting its permissions separately, allowing a window where unauthorized modifications can occur.

What are some common automated tools that detect permission race conditions in applications?

static analysis tools like SAST scanners can identify potential issues by analyzing the sequence of operations during resource copying.

How does PenScan help in detecting and mitigating permission race condition vulnerabilities?

PenScan uses advanced scanning engines to detect instances where resources are copied without proper permissions being set immediately, helping developers mitigate risks proactively.

What is the best practice for securing applications against permission race conditions during resource copy?

The best practice is to ensure that access controls and permissions are applied as soon as a resource is created or modified, closing any potential window of exposure.

Vulnerabilities Related to Permission Race Condition During Resource Copy

| CWE | Name | Relationship | |—|—|—| | CWE-362 | Concurrent Execution using Shared Resource with Improper Synchronization (‘Race Condition’) | ChildOf | | CWE-362 | Concurrent Execution using Shared Resource with Improper Synchronization (‘Race Condition’) | Requires | | CWE-732 | Incorrect Permission Assignment for Critical Resource | Requires |

References

• MITRE - CWE-689
• CAPEC-26
• CAPEC-27
• 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 Permission Race Condition During Resource Copy and other risks before an attacker does.