Schneider Working on Modicon, SoMachine Holes

Friday, April 14, 2017 @ 03:04 PM gHale

Schneider Electric recommends users employ strategic mitigation methods to fend off a use of hard-coded cryptographic key and protection mechanism vulnerabilities in its Modicon M221 PLCs and SoMachine Basic products, according to a report with ICS-CERT.

Simon Heming, Maik Brüggemann, Hendrik Schwartke, and Ralf Spenneberg of Open Source Security discovered these remotely exploitable vulnerabilities. Public exploits are available.

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The vulnerabilities affect the following PLCs and tools for configuring and developing automation machinery:
• Modicon M221 PLC, firmware versions up to v1.5.0.1
• SoMachine Basic, software versions up to v1.5

One vulnerability may allow an attacker to extract a protected project file from the controller to obtain sensitive project information. While the other vulnerability may allow a user with access to a protected project file to decrypt it in order to obtain sensitive information without authorization.

Schneider Electric recommends users store project files in secure, access-restricted locations and encrypt project files with reputable third party file encryption tools. A fix to enhance the SoMachine Basic encryption mechanism will release June 15.

Schneider Electric’s security notice SEVD-2017-097-01 is available.

The products see use in the Commercial Facilities sector. They also see action on a global basis.

Project files, including user-defined project passwords, end up encrypted with a hardcoded password.

CVE-2017-7574 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 10.0.

In the other vulnerability, an attacker can send a specifically crafted command via Modbus over TCP port 502 to the logic controller to discover an application protection password.

CVE-2017-7575 is the case number assigned to this vulnerability, which has a CVSS v3 base score of 10.0.

Schneider Electric recommends users implement the following mitigations until an enhanced encryption mechanism releases June 15:
• Activate Application Protection with a blank password within Modicon M221 applications, as described in section “Password Protecting an Application” of SoMachine Basic online help. This will disable the application upload features of the M221.
• Protect access to controllers using a firewall and blocking all remote/external access to Port 502/TCP.

Schneider Electric’s security notice SEVD-2017-097-02 is available.

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