CVE-2024-40766: SonicWall SonicOS Auth Bypass Vulnerability

CVE-2024-40766 Overview

An improper access control vulnerability has been identified in the SonicWall SonicOS management access, potentially leading to unauthorized resource access and in specific conditions, causing the firewall to crash. This issue affects SonicWall Firewall Gen 5 and Gen 6 devices, as well as Gen 7 devices running SonicOS 7.0.1-5035 and older versions.

Critical Impact

Unauthorized resource access and potential firewall crashes

Affected Products

• SonicWall Firewall Gen 5
• SonicWall Firewall Gen 6
• SonicWall Firewall Gen 7

Discovery Timeline

• Not Available - Vulnerability discovered by Not Available
• Not Available - Responsible disclosure to sonicwall
• Not Available - CVE CVE-2024-40766 assigned
• Not Available - sonicwall releases security patch
• 2024-08-23 - CVE CVE-2024-40766 published to NVD
• 2025-10-31 - Last updated in NVD database

Technical Details for CVE-2024-40766

Vulnerability Analysis

The vulnerability resides in the improper access control mechanisms in SonicWall SonicOS, where insufficient restrictions allow unauthorized access to sensitive resources potentially disrupting firewall operations and causing denial of service conditions.

Root Cause

This vulnerability is due to inadequate handling of access control during SonicOS management interface interactions.

Attack Vector

Network-based actors can exploit this vulnerability remotely without authentication, leveraging open management interfaces to execute unauthorized actions.

// Example exploitation code (sanitized)
#include <stdio.h>
#include <stdlib.h>

int main() {
    printf("Attempting unauthorized access...");
    // Simulated unauthorized command execution
    system("curl http://target-device/api/performUnrestrictedAction?");
    return 0;
}

Detection Methods for CVE-2024-40766

Indicators of Compromise

• Unexplained firewall crashes
• Unauthorized access logs in device management interface
• Unexpected network traffic from management ports

Detection Strategies

IDS/IPS signatures should be updated to detect anomalous access patterns to the management interface. Network monitoring for unusual access from external IPs is recommended.

Monitoring Recommendations

Continuous monitoring of SonicOS logs for unauthorized access attempts and anomalies. Implementing network flow analysis to detect unexpected device behavior is advisable.

How to Mitigate CVE-2024-40766

Immediate Actions Required

• Disable unnecessary management interface access
• Apply IP restriction rules for management interfaces
• Enable logging for all management tasks

Patch Information

Refer to SonicWall's advisory for patch details and apply security updates immediately.

Workarounds

Limiting access to the management interface through VPN or secure tunneling and configuring IP whitelisting can effectively reduce exposure.

# Configuration example
iptables -A INPUT -p tcp --dport 443 -s TRUSTED_IP -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP