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WAGO: Multiple Vulnerabilities in I/O-Check Service in Multiple Devices

VDE-2019-022
Last update
16.12.2019 10:00
Published at
16.12.2019 10:00
Vendor(s)
WAGO GmbH & Co. KG
External ID
VDE-2019-022
CSAF Document

Summary

The reported vulnerabilities allow a remote attacker to change the setting, delete the application, set the device to factory defaults, code execution and to cause a system crash or denial of service.

Note(s)

The following products are affected by the listed vulnerabilities:

Series PFC100 (750-81xx/xxx-xxx)
Series PFC200 (750-82xx/xxx-xxx)

The following products are affected by the vulnerability CVE-2019-5078

750-852, 750-831/xxx-xxx, 750-881, 750-880/xxx-xxx, 750-889

750-823, 750-832/xxx-xxx, 750-862, 750-890/xxx-xxx, 750-891

Impact

These vulnerabilities allow an attacker to manipulate the settings or disturb the basic function of the device via specially crafted IP packets. This can be potentially used to get control of the device.

Affected Product(s)

Model no. Product name Affected versions
750-81xx/xxx-xxx (PFC100) Firmware <FW15
750-823 Firmware <FW15
750-82xx/xxx-xxx (PFC200) Firmware <FW15
750-831/xxx-xxx Firmware <FW15
750-832/xxx-xxx Firmware <FW15
750-852 Firmware <FW15
750-880/xxx-xxx Firmware <FW15
750-881 Firmware <FW15
750-889 Firmware <FW15
750-890/xxx-xxx Firmware <FW15
750-891 Firmware <FW15
750-891 Firmware <FW15

Vulnerabilities

Expand / Collapse all

Published
22.09.2025 14:57
Weakness
Out-of-bounds Write (CWE-787)
Summary

An exploitable stack buffer overflow vulnerability exists in the iocheckd service ''I/O-Check'' functionality of WAGO PFC200 Firmware version 03.01.07(13), WAGO PFC200 Firmware version 03.00.39(12) and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a stack buffer overflow, resulting in code execution. An attacker can send unauthenticated packets to trigger this vulnerability.

References

Published
22.09.2025 14:57
Weakness
Out-of-bounds Write (CWE-787)
Summary

An exploitable stack buffer overflow vulnerability exists in the command line utility getcouplerdetails of WAGO PFC200 Firmware versions 03.01.07(13) and 03.00.39(12), and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets sent to the iocheckd service "I/O-Check" can cause a stack buffer overflow in the sub-process getcouplerdetails, resulting in code execution. An attacker can send unauthenticated packets to trigger this vulnerability.

References

Published
22.09.2025 14:57
Weakness
Out-of-bounds Write (CWE-787)
Summary

An exploitable heap buffer overflow vulnerability exists in the iocheckd service "I/O-Check" functionality of WAGO PFC200 Firmware versions 03.01.07(13) and 03.00.39(12), and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a heap buffer overflow, potentially resulting in code execution. An attacker can send unauthenticated packets to trigger this vulnerability.

References

Published
22.09.2025 14:57
Weakness
Out-of-bounds Write (CWE-787)
Summary

An exploitable heap buffer overflow vulnerability exists in the iocheckd service ''I/O-Chec'' functionality of WAGO PFC 200 Firmware version 03.01.07(13) and 03.00.39(12), and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a heap buffer overflow, potentially resulting in code execution. An attacker can send unauthenticated packets to trigger this vulnerability.

References

Published
22.09.2025 14:57
Weakness
Out-of-bounds Write (CWE-787)
Summary

An exploitable heap buffer overflow vulnerability exists in the iocheckd service I/O-Check functionality of WAGO PFC200 Firmware version 03.01.07(13), WAGO PFC200 Firmware version 03.00.39(12), and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a heap buffer overflow, potentially resulting in code execution. An attacker can send unauthenticated packets to trigger this vulnerability.

References

Published
22.09.2025 14:57
Weakness
Missing Authentication for Critical Function (CWE-306)
Summary

An exploitable denial of service vulnerability exists in the iocheckd service "I/O-Check" functionality of WAGO PFC200 Firmware versions 03.01.07(13) and 03.00.39(12), and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets can cause a denial of service, resulting in the device entering an error state where it ceases all network communications. An attacker can send unauthenticated packets to trigger this vulnerability.

References

Published
22.09.2025 14:57
Weakness
Exposure of Sensitive Information to an Unauthorized Actor (CWE-200)
Summary

An exploitable information exposure vulnerability exists in the iocheckd service "I/O-Check" functionality of WAGO PFC200 Firmware versions 03.01.07(13) and 03.00.39(12), and WAGO PFC100 Firmware version 03.00.39(12). A specially crafted set of packets can cause an external tool to fail, resulting in uninitialized stack data to be copied to the response packet buffer. An attacker can send unauthenticated packets to trigger this vulnerability.

References

Mitigation

Restrict network access to the device.
Do not directly connect the device to the internet.
Disable unused TCP/UDP-ports

Remediation

The I/O-Check service protocol is only needed during installation and commissioning, not during normal operations. It is highly recommended to disable the IP-port 6626 after commissioning. This is the easiest and securest way to protect your device for the listed vulnerabilities and for upcoming zero day exploits.

Regardless of the action described above, the following CVEs can be fixed alternatively by a firmware update >= FW 15.

CVE-2019-5073

CVE-2019-5074

CVE-2019-5075

CVE-2019-5079

CVE-2019-5081

CVE-2019-5082

Revision History

Version Date Summary
1 16.12.2019 10:00 Initial revision.