Rewterz Threat Advisory – Industrial Control Moxa – IKS & EDS Multiple Vulnerabilities

Severity

High

Analysis Summary

Following remotely exploitable vulnerabilities have been found in MOXA’s IKS and EDS equipment.

Vulnerabilities:

CVE-2019-6557:

Classic Buffer Overflow Several buffer overflow vulnerabilities have been identified, which may allow remote code execution.

CVE-2019-6561:

Cross-site Request Forgery A cross-site request forgery has been identified, which may allow for the execution of unauthorized actions on the device.

CVE-2019-6565:

Cross-site Scripting The device fails to properly validate user input, giving unauthenticated and authenticated attackers the ability to perform XSS attacks, which may be used to send a malicious script.

CVE-2019-6520:

Improper Access Controls The device does not properly check authority on server side, which results in a read-only user being able to perform arbitrary configuration changes.

CVE-2019-6524:

Improper Restriction of Excessive Authentication Attempts The devices do not implement sufficient measures to prevent multiple failed authentication attempts, which may allow an attacker to discover passwords via brute force attack.

CVE-2019-6526:

Missing Encryption of Sensitive Data The devices use plaintext transmission of sensitive data, which may allow an attacker to capture sensitive data such as an administrative password.

CVE-2019-6522:

Out-of-bounds Read, Failure to properly check array bounds may allow an attacker to read device memory on arbitrary addresses, which may allow an attacker to retrieve sensitive data or cause device reboot.

CVE-2019-6518:

Unprotected Storage of Credentials The devices store plaintext passwords, which may allow sensitive information to be read by someone with access to the device.

CVE-2019-6563:

Predictable from Observable State The software generates a predictable cookie calculated with an MD5 hash, allowing an attacker to capture the administrator’s password, which could lead to a full compromise of the device.

CVE-2019-6559:

Uncontrolled Resource Consumption The devices allow remote authenticated users to cause a denial of service via a specially crafted packet, which may cause the switch to crash.

Impact

• Exposure of sensitive information
• Remote Code Execution
• Arbitrary configuration changes
• Authentication bypass
• Sensitive data capture
• Reboot of the device
• Device crash
• Full compromise of the device

Affected Vendors

Moxa

Affected Products

• IKS-G6824A series Versions 4.5 and prior
• EDS-405A series Version 3.8 and prior
• EDS-408A series Version 3.8 and prior
• EDS-510A series Version 3.8 and prior.

Remediation

Moxa recommends that users implement the following measures to mitigate these vulnerabilities.

• Install firmware patch. Patches may be requested from Moxa Customer Service at the following link (login required): https://www.moxa.com/support/request_support.aspx
• Disable web console access in IKS and use another console such as SNMP/Telnet/CLI instead.
• Set EDS series Web configuration as “https only” to reduce predictable session ID concern.
• Minimize network exposure for all control system devices and/or systems, and ensure that they are not accessible from the Internet.
• Locate control system networks and remote devices behind firewalls, and isolate them from the business network.