CVE-2023-29464: FactoryTalk Linx Information Disclosure

CVE-2023-29464 Overview

CVE-2023-29464 is a critical vulnerability affecting FactoryTalk Linx in Rockwell Automation PanelView Plus devices. The flaw allows an unauthenticated threat actor to read sensitive data from memory by sending crafted malicious packets over the Common Industrial Protocol (CIP). When an attacker sends a size value larger than the allocated buffer, the system leaks data from memory, resulting in information disclosure. If the size parameter is large enough, it can cause CIP communications to become completely unresponsive, leading to a denial-of-service condition.

This vulnerability is particularly concerning in industrial control system (ICS) environments where FactoryTalk Linx serves as a critical communication component between human-machine interfaces (HMIs) and programmable logic controllers (PLCs).

Critical Impact

Unauthenticated remote attackers can extract sensitive memory contents and cause denial-of-service conditions on industrial control systems, potentially disrupting manufacturing and critical infrastructure operations.

Affected Products

• Rockwell Automation FactoryTalk Linx version 6.20
• Rockwell Automation FactoryTalk Linx version 6.30
• Rockwell Automation PanelView Plus devices running affected FactoryTalk Linx versions

Discovery Timeline

• 2023-10-13 - CVE-2023-29464 published to NVD
• 2024-11-21 - Last updated in NVD database

Technical Details for CVE-2023-29464

Vulnerability Analysis

This vulnerability stems from improper input validation (CWE-20) that enables an out-of-bounds read condition, potentially leading to an out-of-bounds write (CWE-787). The flaw exists in how FactoryTalk Linx processes incoming CIP packets, specifically in the handling of size parameters within packet headers.

When the application receives a CIP packet, it uses the size value provided in the packet to determine how much data to read. The vulnerability occurs because the application fails to properly validate whether this size value exceeds the actual buffer allocation. By manipulating the size field to specify a value larger than the legitimate buffer, an attacker can force the application to read beyond the intended memory boundaries.

The impact is twofold: first, sensitive data from adjacent memory regions can be leaked back to the attacker, potentially exposing configuration data, credentials, or other sensitive operational information. Second, if the specified size is sufficiently large, the malformed request can crash or hang the CIP communication handler, rendering the FactoryTalk Linx service unresponsive to all subsequent legitimate traffic.

Root Cause

The root cause of CVE-2023-29464 is improper input validation in the packet parsing logic of FactoryTalk Linx. The application trusts the size parameter provided in incoming CIP packets without verifying that it falls within expected bounds. This missing boundary check allows attackers to specify arbitrary size values, leading to out-of-bounds memory access operations.

Attack Vector

The attack is network-based and requires no authentication or user interaction. An attacker with network access to the CIP service port can exploit this vulnerability remotely by:

1. Crafting a malicious CIP packet with a size field value exceeding the expected buffer size
2. Sending the packet to the target FactoryTalk Linx service
3. Receiving the response containing leaked memory data (for information disclosure)
4. Optionally sending packets with extremely large size values to trigger denial-of-service

The attack leverages the Common Industrial Protocol, which is standard in Rockwell Automation environments and typically operates on TCP port 44818.

Detection Methods for CVE-2023-29464

Indicators of Compromise

• Anomalous CIP traffic patterns with unusually large packet size values targeting FactoryTalk Linx services
• Unexpected crashes or restarts of the FactoryTalk Linx process on PanelView Plus devices
• Network logs showing repeated connection attempts to CIP ports from unauthorized sources
• Memory consumption anomalies or service hangs in FactoryTalk Linx applications

Detection Strategies

• Deploy network intrusion detection systems (IDS) with signatures for malformed CIP packet detection
• Monitor CIP traffic for packets with size parameters exceeding normal operational bounds
• Implement deep packet inspection on industrial network segments to identify exploitation attempts
• Configure alerts for FactoryTalk Linx service failures or unexpected restarts

Monitoring Recommendations

• Enable detailed logging on all FactoryTalk Linx instances and centralize log collection for analysis
• Monitor network traffic on TCP port 44818 and other CIP-related ports for suspicious activity
• Implement baseline analysis for CIP communication patterns to detect anomalies
• Regularly audit network access to industrial control systems to identify unauthorized connection sources

How to Mitigate CVE-2023-29464

Immediate Actions Required

• Apply the security patches provided by Rockwell Automation as documented in their security advisory
• Restrict network access to FactoryTalk Linx services using firewalls and access control lists
• Isolate affected PanelView Plus devices on segmented industrial networks with limited external connectivity
• Disable or restrict CIP access from untrusted network segments until patches can be applied

Patch Information

Rockwell Automation has released security updates to address this vulnerability. Organizations should consult the Rockwell Automation Support Answer (ID: 1141040) for detailed patch information, affected version specifics, and upgrade instructions.

Ensure all FactoryTalk Linx installations are updated beyond versions 6.20 and 6.30 with the latest security patches applied. Follow Rockwell Automation's recommended upgrade path and validate system functionality after patching.

Workarounds

• Implement network segmentation to isolate industrial control systems from untrusted networks
• Deploy application-layer firewalls capable of inspecting and filtering CIP traffic
• Use VPNs or encrypted tunnels for any remote access to FactoryTalk Linx services
• Disable CIP services on systems where they are not operationally required