Headline
CVE-2021-34566: VDE-2020-036 | CERT@VDE
In WAGO I/O-Check Service in multiple products an unauthenticated remote attacker can send a specially crafted packet containing OS commands to crash the iocheck process and write memory resulting in loss of integrity and DoS.
2021-06-29 12:00 (CEST) VDE-2020-036
WAGO: Multiple Vulnerabilities in I/O-Check Service
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Published
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2021-06-29 12:00 (CEST)
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Last update
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2021-06-29 12:00 (CEST)
Vendor(s)
WAGO GmbH & Co. KG
Product(s)
Article No°
Product Name
Affected Version(s)
750-81xx/xxx-xxx
<= FW18 Patch 2
750-82xx/xxx-xxx
<= FW18 Patch 2
752-8303/8000-0002
<= FW18 Patch 2
762-4xxx
<= FW18 Patch 2
762-5xxx
<= FW18 Patch 2
762-6xxx
<= FW18 Patch 2
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Summary
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Multiple vulnerabilities in the WAGO I/O-Check Service were reported.
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Vulnerabilities
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Summary
An attacker can send a specially crafted packet containing OS commands to crash the diagnostic tool and write memory.
Summary
An attacker can send a specially crafted packet containing OS commands to crash the iocheck process and write memory.
Summary
An attacker can send a specially crafted packet containing OS commands to provoke a denial of service and an out-of-bounds read.
Weakness
Allocation of Resources Without Limits or Throttling (CWE-770)
Summary
An attacker can send a specially crafted packet containing OS commands to provoke a denial of service.
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Impact
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By exploiting the described vulnerabilities, the attacker potentially is able to manipulate or disrupt the device.
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Solution
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Mitigation
- Disable I/O-Check service
- Restrict network access to the device.
- Do not directly connect the device to the internet.
Solution
The I/O-Check service protocol is only needed during installation and commissioning, not during normal operations. It is highly recommended to disable the I/O-Check service after commissioning. This is the easiest and securest way to protect your device from the listed vulnerabilities and possible upcoming zero-day exploits.
Regardless to the action described above, the vulnerability has been fixed in FW18 Patch 3, released in June 2021.
We recommend all affected users to update to the latest firmware version.
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Reported by
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These vulnerabilities were reported to WAGO by Uri Katz of Claroty. We thank CERT@VDE for the management of this coordinated disclosure.