Upgraded GE Switches Fix Vulnerabilities

Wednesday, January 14, 2015 @ 12:01 PM gHale


GE is recommending users upgrade switch firmware and disable the configuration web server to mitigate vulnerabilities in the Multilink ML800 series managed switches, according to a report on ICS-CERT.

GE Digital Energy validated these vulnerabilities, discovered by Eireann Leverett of IOActive, and confirmed the issues affecting the ML800 will also affect the MultiLink series of managed Ethernet switches including the ML1200, ML1600, ML2400, ML810, ML3000, and ML3100.

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These remotely exploitable vulnerabilities ended up publicly disclosed.

The following GE Multilink Ethernet switch suffers from the issue:
• GE Multilink ML800/1200/1600/2400 Version 4.2.1and prior
• GE Multilink ML810/3000/3100 series switch Version 5.2.0 and prior

The GE Multilink ML800 is subject to unauthorized access via hard-coded credentials. In addition, there can be an impact on availability via attacks composed of specifically crafted packets to the web server resulting in switch performance degradation. If attacks continue, the web server would be subject to a denial of service.

GE is a US-based company that maintains offices in several countries around the world.

The Multilink ML800 series switch is a compact, hardened managed Ethernet switch designed specifically for use in industrial facilities, substations, and transportation environments. It provides high-speed networking with management functions and support for industrial/utility protocols and applications. According to GE, GE Multilink ML800 series switches see action globally across several sectors including critical manufacturing, energy, and water and wastewater systems.

Using specially crafted packets the device can end up forced to exhaust its resources until performance degrades. Repeated malicious packets will exhaust the switch resources and cause the device to reboot in order to restore availability.

CVE-2014-5418 is the case number assigned to this vulnerability, which has a CVSS v2 base score of 5.0.

The RSA private key used to decrypt SSL traffic in the switch can end up obtained from the firmware allowing malicious users to decrypt traffic.

CVE-2014-5419 is the case number assigned to this vulnerability, which has a CVSS v2 base score of 10.0.

No known public exploits specifically target these vulnerabilities, however, an attacker with a low skill would be able to exploit these vulnerabilities.

GE recommended users update the switch firmware to the latest published version to enable new keys to end up calculated and exchanged. The latest firmware is Version 4.2.1 for the ML800, ML1200, ML1600 and ML2400 and Version 5.2.0 for the ML810, ML3000, and ML3100. Firmware updates are available from GE through the “Resources/Software” link in the product brochures.

ICS-CERT and GE recommend updating the switch over a serial connection to prevent an attacker from capturing the new key.

The slow data transfer DoS attack affects the web interface used to configure the device with a web browser. When deploying the device into a production environment, the web server should end up disabled in order to effectively mitigate this vulnerability. After disabling the web interface, a user remains able to configure the device locally or remotely through the command line interfaces without risk of this attack. By connecting to the command line interface through serial terminal or telnet, it is possible to disable the web server.

Click on the GE Advisory for specific information on how to install the firmware, change RSA key, and disable the web server.



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