Telvent’s Improper Frame Padding Fixed

Thursday, March 10, 2016 @ 05:03 PM gHale

Schneider Electric already released a revision that eliminates a vulnerability caused by an Institute of Electrical and Electronics Engineers (IEEE) conformance issue involving improper frame padding in its Telvent SAGE 2300 and 2400 remote terminal units (RTUs), according to a report on ICS-CERT.

This advisory is a notification of a new vulnerability in the previous software version. Researchers David Formby and Raheem Beyah of Georgia Tech, who discovered the issue, tested the revision to validate it resolves the reported vulnerability.

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The following Schneider Electric Telvent RTUs suffer from the issue:
• Sage 3030M, with firmware prior to C3414-500-S02J2;
• Sage 1410, with firmware prior to C3414-500-S02J2;
• Sage1430, with firmware prior to C3414-500-S02J2;
• Sage 1450, with firmware prior to C3414-500-S02J2;
• LANDAC II-2, with firmware prior to C3414-500-S02J2;
• Sage 2300, with firmware prior to C3413-500-S01; and
• Sage 2400, with firmware prior to C3414-500-S02J2 (released March 2015.)

IEEE 802 specifies packets have a minimum size of 56 bytes. The Ethernet driver should fill the data field with octets of zero for padding when packets are less than 56 bytes. Resident memory and other data end up used for padding in some implementations that could cause information leakage. This attack is passive; the attacker can only see data the affected device sent out as part of a packet.

Schneider Electric is a Paris, France-based company that maintains offices in 190 countries worldwide.

The affected products, Telvent Sage 2300/2400 RTUs, are industrial data communications devices. These products see action across several sectors including the energy sector. Schneider Electric estimates these products see use primarily in North America.

The data padding within the data field of the Ethernet pack should be all zeros. The previous implementation of firmware allowed other data from a known area of memory to end up used in this field and could exfiltrate or leak data.

CVE-2015-6485 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 5.3.

The attacker would need to be the receiver of the packet (that contains leaked data) or along the path (e.g., on a local network that does not use encryption).

ICS-CERT is unaware of any exploits that target this vulnerability. However, an attacker with a low skill would be able to exploit this vulnerability. This is a passive attack; the attacker can only access the data contained within the packet.

Click here for Schneider-Electric’s customer web site for access to all Sage RTU vulnerability and update information.

The Telvent Sage 2300 is end of life for security patches, and customers should move to the Sage 2400 platform.

The Telvent SAGE 2300 family is end of life and no longer supported by Schneider Electric. The Telvent SAGE 2400 family is still supported and maintained with patches.