CVE-2024-35293: Authentication Bypass Vulnerability

CVE-2024-35293 Overview

CVE-2024-35293 is a critical Missing Authentication for Critical Function vulnerability (CWE-306) affecting Schneider Elektronik devices. An unauthenticated remote attacker may exploit this vulnerability to reboot or erase the affected devices, resulting in data loss and/or a denial of service (DoS) condition.

Critical Impact

Unauthenticated remote attackers can reboot or completely erase affected devices over the network, causing significant data loss and service disruption without requiring any credentials.

Affected Products

• Schneider Elektronik devices (refer to Schneider Elektronik Security Report for specific product details)

Discovery Timeline

• 2024-10-02 - CVE-2024-35293 published to NVD
• 2024-10-04 - Last updated in NVD database

Technical Details for CVE-2024-35293

Vulnerability Analysis

This vulnerability represents a fundamental authentication bypass flaw where critical device functions are exposed without requiring any form of authentication. The affected devices fail to implement proper authentication mechanisms for sensitive administrative operations, allowing any network-accessible attacker to perform destructive actions.

The vulnerability is particularly severe because it enables two highly impactful attack scenarios: device rebooting (causing service interruption) and device erasure (causing permanent data loss). Both attacks can be executed remotely over the network without any user interaction or prior authentication, making this an ideal target for automated attacks or opportunistic threat actors.

Root Cause

The root cause of CVE-2024-35293 is a Missing Authentication for Critical Function (CWE-306). The affected Schneider Elektronik devices expose administrative endpoints or commands that should require authentication but do not. This design flaw allows unauthenticated users to access and execute critical functions such as device reboot and data erasure operations.

This type of vulnerability typically arises from:

• Improperly secured administrative interfaces
• Missing or incomplete implementation of authentication checks on sensitive API endpoints
• Legacy device designs that assumed network isolation would provide sufficient security

Attack Vector

The attack vector for this vulnerability is network-based. An attacker with network access to the vulnerable device can send specially crafted requests to trigger the reboot or erase functions without providing any authentication credentials.

The attack requires:

• Network connectivity to the target device
• Knowledge of the vulnerable endpoint or command structure
• No authentication credentials or special privileges

For technical details on the specific attack methodology, refer to the Schneider Elektronik Security Report.

Detection Methods for CVE-2024-35293

Indicators of Compromise

• Unexpected device reboots without administrative action or scheduled maintenance
• Missing or corrupted data on affected devices indicating unauthorized erasure
• Network traffic logs showing requests to administrative endpoints from unauthorized sources
• Multiple devices experiencing simultaneous service disruptions

Detection Strategies

• Monitor network traffic for unauthenticated requests to device management interfaces
• Implement network segmentation and monitor for unauthorized access attempts to industrial control systems
• Deploy intrusion detection systems (IDS) with signatures for known attack patterns against Schneider Elektronik devices
• Review device logs for unexpected reboot events or configuration changes

Monitoring Recommendations

• Enable and centralize logging for all affected Schneider Elektronik devices
• Implement network flow monitoring to detect anomalous traffic patterns to device management ports
• Set up alerts for device availability changes to quickly identify potential exploitation
• Conduct regular integrity checks on device configurations and stored data

How to Mitigate CVE-2024-35293

Immediate Actions Required

• Isolate affected Schneider Elektronik devices from untrusted networks immediately
• Implement network segmentation to restrict access to management interfaces
• Deploy firewall rules to limit access to affected devices to authorized IP addresses only
• Review the Schneider Elektronik Security Report for vendor-specific guidance

Patch Information

Consult the Schneider Elektronik Security Report (SAR-202405-1) for official patch information and firmware updates. Apply vendor-provided patches as soon as they become available after testing in a non-production environment.

Workarounds

• Place affected devices behind a properly configured firewall that restricts management interface access
• Implement VPN or other secure remote access solutions for administrative access
• Use network access control (NAC) to restrict which systems can communicate with affected devices
• Enable any available logging or monitoring features on affected devices to detect exploitation attempts

# Example firewall rule to restrict device management access (adjust IP and port as needed)
# Allow only trusted management subnet
iptables -A INPUT -s 10.10.10.0/24 -d <device_ip> -p tcp --dport <mgmt_port> -j ACCEPT
# Block all other access to management port
iptables -A INPUT -d <device_ip> -p tcp --dport <mgmt_port> -j DROP