Industrial Control Systems Vulnerable to Shellshock, Heartbleed

The ICS-CERT has outlined an SSH key issue in industrial control systems that are often used to power utilities and critical infrastructure networks. But, the initial vulnerability is only the tip of the iceberg, with Shellshock, Heartbleed and other flaws also in full effect.

According to ICS-CERT, Advantech EKI series products, which are Modbus gateways used to connect serial devices to TCP/IP networks, are vulnerable to attackers looking to intercept communications to and from the devices. The attack can be done remotely.

Advantech has released firmware version 1322_D1.98 in response to the ICS-CERT advisory, but it turns out that the fix is deeply flawed.

Rapid7 discovered the flaws during a firmware analysis specific to the EKI-1322 GPRS IP gateway device, but “given the scope of ICSA-15-309-01, it is presumed these issues are present on other EKI products,” the firm said.

Rapid7 uncovered three issues, including the fact that the product includes the bash shell, version 2.05, which is vulnerable to the Shellshock vulnerability. The product also includes OpenSSL version 1.0.0e, which is vulnerable to the Heartbleed vulnerability as well as a number of other issues. And, the DHCP client is version 1.3.20-pl0, which appears to be vulnerable to a number of known issues, including CVE-2012-2152.

All three problems require an update from the vendor in order to update the shipping software to versions patched against the named issues. End users of these devices are advised to ensure that these devices are not reachable by untrusted networks such as the internet. Unfortunately, these issues are not newly discovered vulnerabilities, but rather known vulnerabilities that are shipping on production industrial control systems today.

ICS-CERT recommends that users take defensive measures to minimize the risk of exploitation of these vulnerabilities. Specifically, users should:

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.

When remote access is required, use secure methods, such as VPNs, recognizing that VPNs may have vulnerabilities and should be updated to the most current version available. Also recognize that VPN is only as secure as the connected devices that use them.

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