CVE-2018-8840 – This vulnerability allows remote attackers to e... (How to Fix)

Q: What is the severity of CVE-2018-8840?

CVE-2018-8840 has a CVSS score of 9.8 (CRITICAL). This vulnerability allows remote attackers to execute arbitrary code on industrial control systems by sending specially crafted packets during tag, alarm, or event operations. It affects InduSoft Web Studio and InTouch Machine Edition SCADA/HMI software, potentially compromising critical infrastructure systems.

📋 TL;DR

This vulnerability allows remote attackers to execute arbitrary code on industrial control systems by sending specially crafted packets during tag, alarm, or event operations. It affects InduSoft Web Studio and InTouch Machine Edition SCADA/HMI software, potentially compromising critical infrastructure systems.

💻 Affected Systems

Products:

InduSoft Web Studio
InTouch Machine Edition

Versions: v8.1 and prior versions

Operating Systems: Windows

Default Config Vulnerable: ⚠️ Yes

Notes: Affects systems using tag, alarm, or event operations. Industrial control systems in manufacturing, energy, and critical infrastructure are particularly at risk.

📦 What is this software?

Intouch Machine Edition 2017 by Industrial Software

View all CVEs affecting Intouch Machine Edition 2017 →

Web Studio by Indusoft

View all CVEs affecting Web Studio →

⚠️ Risk & Real-World Impact

🔴

Worst Case

Complete system compromise allowing attacker to manipulate industrial processes, cause physical damage, or disrupt critical infrastructure operations.

🟠

Likely Case

Remote code execution leading to data theft, system manipulation, or ransomware deployment on industrial control networks.

🟢

If Mitigated

Limited impact if systems are properly segmented, monitored, and have network controls preventing unauthorized access.

🌐 Internet-Facing: HIGH - Systems exposed to internet are extremely vulnerable to remote exploitation without authentication.

🏢 Internal Only: HIGH - Even internally, the vulnerability can be exploited by attackers who gain network access through other means.

🎯 Exploit Status

Public PoC: ⚠️ Yes

Weaponized: LIKELY

Unauthenticated Exploit: ⚠️ Yes

Complexity: LOW

Exploitation requires sending crafted packets to vulnerable systems during specific operations. Public exploit code exists in security research repositories.

🛠️ Fix & Mitigation

✅ Official Fix

Patch Version: Update to versions after v8.1

Vendor Advisory: http://software.schneider-electric.com/pdf/security-bulletin/lfsec00000125/

Restart Required: Yes

Instructions:

1. Download and install the latest version from Schneider Electric. 2. Apply all security patches. 3. Restart affected systems. 4. Verify installation and test functionality.

🔧 Temporary Workarounds

Network Segmentation

all

Isolate SCADA/HMI systems from untrusted networks using firewalls and VLANs

Access Control

all

Implement strict network access controls to limit communication to authorized systems only

🧯 If You Can't Patch

Implement strict network segmentation to isolate vulnerable systems from untrusted networks
Deploy intrusion detection systems to monitor for exploitation attempts and anomalous traffic patterns

🔍 How to Verify

Check if Vulnerable:

Check software version in application about dialog or registry: HKEY_LOCAL_MACHINE\SOFTWARE\InduSoft\Web Studio\Version

Check Version:

reg query "HKLM\SOFTWARE\InduSoft\Web Studio" /v Version

Verify Fix Applied:

Verify version is greater than 8.1 and check for applied security patches in vendor documentation

📡 Detection & Monitoring

Log Indicators:

Unusual network connections to SCADA/HMI ports
Multiple failed tag/alarm operations
Unexpected process creation

Network Indicators:

Malformed packets to SCADA/HMI ports
Unusual traffic patterns during tag operations
Connection attempts from unauthorized IPs

SIEM Query:

source_ip=* AND dest_port IN (TCP/port_range) AND packet_size>threshold AND protocol=SCADA

📊 Metadata

CVE ID: CVE-2018-8840

CVSS v3 Score: 9.8 (CRITICAL)

CVSS Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

CWE: CWE-121

Published: April 18, 2018

Last Updated: November 21, 2024

🔗 References

http://software.schneider-electric.com/pdf/security-bulletin/lfsec00000125/ Third Party Advisory
http://www.securityfocus.com/bid/103949 Third Party Advisory,VDB Entry
https://ics-cert.us-cert.gov/advisories/ICSA-18-107-01 Third Party Advisory,US Government Resource
https://www.tenable.com/security/research/tra-2018-07 Third Party Advisory
http://software.schneider-electric.com/pdf/security-bulletin/lfsec00000125/ Third Party Advisory
http://www.securityfocus.com/bid/103949 Third Party Advisory,VDB Entry
https://ics-cert.us-cert.gov/advisories/ICSA-18-107-01 Third Party Advisory,US Government Resource
https://www.tenable.com/security/research/tra-2018-07 Third Party Advisory

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🔗 Related Vulnerabilities

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