CVE-2024-10511: Authentication Bypass Vulnerability

CVE-2024-10511 Overview

CVE-2024-10511 is an Improper Authentication vulnerability (CWE-287) that affects Schneider Electric products with web interfaces. The vulnerability exists due to insufficient authentication controls that could allow an attacker on the local network to cause a Denial of Service condition by repeatedly requesting the /accessdenied URL endpoint. This repeated access triggers a lockout mechanism that prevents legitimate users from accessing the web management interface.

Critical Impact

Attackers on the local network can deny access to the web management interface by exploiting improper authentication handling, potentially disrupting operational monitoring and management capabilities.

Affected Products

• Schneider Electric products with web interfaces (refer to Schneider Electric Security Notice SEVD-2024-345-01 for specific product versions)

Discovery Timeline

• 2024-12-11 - CVE-2024-10511 published to NVD
• 2024-12-11 - Last updated in NVD database

Technical Details for CVE-2024-10511

Vulnerability Analysis

This vulnerability stems from improper authentication handling in the web interface component of affected Schneider Electric products. The flaw is classified under CWE-287 (Improper Authentication), which encompasses scenarios where software does not sufficiently verify that a user or entity is who they claim to be before allowing access to restricted functionality or data.

The exploitation mechanism is straightforward: an attacker positioned on the local network can repeatedly send HTTP requests to the /accessdenied URL endpoint. This endpoint, which is typically used to display access denied messages to unauthorized users, contains a flaw in how it handles repeated requests. When bombarded with requests, the authentication mechanism erroneously triggers protective lockout measures that affect all users, including legitimate administrators attempting to access the web interface.

The attack requires network adjacency, meaning the attacker must have access to the same local network segment as the target device. No authentication or user interaction is required to execute this attack, making it easily exploitable by any malicious actor with local network access.

Root Cause

The root cause of CVE-2024-10511 is an improper implementation of the authentication denial mechanism in the web interface. The /accessdenied endpoint fails to properly distinguish between legitimate access denial scenarios and malicious request flooding. The system incorrectly applies rate limiting or lockout policies based on repeated requests to this URL, rather than implementing proper per-user or per-session authentication controls. This design flaw allows unauthenticated network users to trigger denial conditions that affect the availability of the web interface for all users.

Attack Vector

The attack vector for CVE-2024-10511 is network-based and can be executed by any user with access to the local network where the vulnerable device resides. The attacker does not need any prior authentication or special privileges to carry out this attack.

The exploitation process involves sending rapid, repeated HTTP requests to the /accessdenied URL endpoint. This flooding of requests exploits the improper authentication handling, causing the web interface to become inaccessible. The attack effectively creates a Denial of Service condition for the management interface, preventing administrators from performing monitoring, configuration, or troubleshooting tasks through the web UI.

Since no verified code examples are available for this vulnerability, organizations should refer to the Schneider Electric Security Notice SEVD-2024-345-01 for detailed technical information regarding the exploitation mechanism and affected endpoints.

Detection Methods for CVE-2024-10511

Indicators of Compromise

• Unusual volume of HTTP requests targeting the /accessdenied endpoint from a single source IP address
• Web interface access failures or lockouts affecting multiple legitimate users simultaneously
• Network traffic patterns showing repeated requests to the /accessdenied URL at high frequency
• User complaints about inability to access the web management interface despite correct credentials

Detection Strategies

• Deploy network intrusion detection systems (IDS) with rules to detect high-frequency requests to the /accessdenied endpoint
• Implement web application firewall (WAF) rules to rate-limit requests to sensitive authentication-related endpoints
• Configure SIEM alerting for anomalous HTTP request patterns targeting Schneider Electric device web interfaces
• Monitor authentication logs for unusual patterns of access denial events

Monitoring Recommendations

• Enable detailed logging on affected Schneider Electric devices to capture all web interface access attempts
• Establish baseline metrics for normal /accessdenied endpoint access frequency to detect anomalies
• Implement real-time alerting for sudden spikes in authentication denial events
• Monitor network traffic between internal hosts and affected devices for unusual request patterns

How to Mitigate CVE-2024-10511

Immediate Actions Required

• Review and apply security patches or firmware updates from Schneider Electric as referenced in the Security Notice SEVD-2024-345-01
• Implement network segmentation to limit access to affected device management interfaces
• Deploy rate limiting controls at the network perimeter for traffic destined to vulnerable devices
• Restrict web interface access to trusted management workstations only

Patch Information

Schneider Electric has released security guidance for this vulnerability. Organizations should consult the official Schneider Electric Security Notice SEVD-2024-345-01 for specific patch details, affected product versions, and remediation instructions. Apply all recommended firmware updates and security patches as soon as they become available for your specific product deployment.

Workarounds

• Implement firewall rules to restrict access to the web interface from trusted IP addresses only
• Deploy a reverse proxy with rate limiting capabilities in front of the web interface
• Use VPN or network access control to ensure only authorized devices can reach the management interface
• Consider disabling the web interface temporarily if not operationally critical and alternative management methods are available

# Example firewall rule to restrict web interface access (adapt to your environment)
# Allow only trusted management network to access device web interface
iptables -A INPUT -p tcp --dport 80 -s 10.10.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s 10.10.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP