CVE-2023-23585: Honeywell Experion Server DoS Vulnerability

CVE-2023-23585 Overview

CVE-2023-23585 is a heap overflow vulnerability affecting Honeywell Experion Server and related industrial control system (ICS) components. The vulnerability occurs during the handling of a specially crafted message for a specific configuration operation, which can lead to a denial of service (DoS) condition. This vulnerability is particularly concerning as it affects critical industrial control systems commonly deployed in process automation environments.

Critical Impact

Successful exploitation of this heap overflow vulnerability can cause a denial of service condition in Honeywell Experion servers, potentially disrupting critical industrial process control operations.

Affected Products

• Honeywell Experion Server
• Honeywell Experion Station
• Honeywell Engineering Station
• Honeywell Direct Station

Discovery Timeline

• 2023-07-13 - CVE-2023-23585 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-23585

Vulnerability Analysis

This vulnerability is classified as CWE-787 (Out-of-bounds Write), which encompasses heap overflow conditions. The flaw exists in the Experion server's message handling functionality, specifically when processing configuration operations. When a maliciously crafted message is sent to the server, it triggers an out-of-bounds write condition in the heap memory region. This memory corruption can destabilize the server process, resulting in a crash or unresponsive state.

The network-accessible nature of this vulnerability means that an unauthenticated remote attacker can potentially trigger the DoS condition without requiring any user interaction or special privileges. In industrial control system environments, such disruptions can have significant operational implications, potentially affecting process visibility and control capabilities.

Root Cause

The root cause of CVE-2023-23585 lies in improper bounds checking when the Experion server processes incoming configuration messages. The server fails to adequately validate the size or structure of incoming data before writing it to heap-allocated memory buffers. This oversight allows an attacker to craft a message that causes the server to write data beyond the allocated buffer boundaries, corrupting adjacent heap memory structures and leading to process instability.

Attack Vector

The attack vector for this vulnerability is network-based. An attacker with network access to the Experion server can send a specially crafted message targeting the configuration operation handler. The attack does not require authentication, prior access, or user interaction, making it relatively straightforward to exploit for denial of service purposes.

The exploitation scenario involves:

1. The attacker identifies a network-accessible Honeywell Experion server
2. A malformed configuration message is crafted with oversized or malformed data fields
3. The message is transmitted to the server over the network
4. The server's message handler attempts to process the malformed data
5. The heap overflow occurs, corrupting memory and causing the service to crash or become unresponsive

Detection Methods for CVE-2023-23585

Indicators of Compromise

• Unexpected crashes or restarts of Honeywell Experion server processes
• Unusual network traffic patterns targeting Experion server communication ports
• Memory access violation errors or heap corruption messages in system logs
• Abnormal configuration operation requests from unexpected source IP addresses

Detection Strategies

• Deploy network intrusion detection systems (IDS) with rules to identify malformed configuration messages targeting Experion servers
• Implement application-level monitoring to detect unusual message sizes or malformed packet structures
• Enable detailed logging on Experion servers to capture and analyze configuration operation requests
• Monitor for process crashes or service disruptions that may indicate exploitation attempts

Monitoring Recommendations

• Establish baseline network communication patterns for Experion infrastructure and alert on deviations
• Configure SIEM rules to correlate Experion server crashes with preceding network activity
• Implement real-time monitoring of heap memory usage on critical Experion server systems
• Deploy SentinelOne Singularity platform for endpoint protection and behavioral analysis of ICS workstations

How to Mitigate CVE-2023-23585

Immediate Actions Required

• Review and apply network segmentation to isolate Experion servers from untrusted network segments
• Implement firewall rules to restrict access to Experion servers to only authorized systems and personnel
• Monitor Honeywell security notifications for available patches and updates
• Enable enhanced logging on Experion systems to detect potential exploitation attempts

Patch Information

Honeywell has acknowledged this vulnerability and recommends consulting the Honeywell Security Resource for specific recommendations on upgrading and versioning. Organizations should contact Honeywell support or access the Honeywell Process Solutions security portal to obtain the appropriate security patches for their specific Experion PKS version and deployment configuration.

Workarounds

• Implement strict network access controls using firewalls and access control lists to limit connectivity to Experion servers
• Deploy network monitoring to detect and block potentially malicious configuration messages
• Consider implementing application-layer gateways or proxies that can validate message integrity before forwarding to Experion servers
• Ensure backup and recovery procedures are in place to quickly restore service in the event of a successful DoS attack

# Network segmentation example using firewall rules
# Restrict Experion server access to authorized management networks only
# Adjust ports and IP ranges according to your deployment

# Example iptables rules for Linux-based firewalls
iptables -A INPUT -s 10.0.100.0/24 -d 10.0.50.10 -p tcp --dport 443 -j ACCEPT
iptables -A INPUT -s 0.0.0.0/0 -d 10.0.50.10 -p tcp --dport 443 -j DROP

# Document all authorized source IPs for Experion server communication
# Implement logging for denied connection attempts