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ID

VDE-2020-042

Published

2020-10-27 11:28 (CET)

Last update

2021-03-03 13:20 (CET)

Vendor(s)

WAGO

Product(s)

  • 750-352
  • 750-831/xxx-xxx
  • 750-852
  • 750-880/xxx-xxx
  • 750-881
  • 750-889

UPDATE A:

  • 750-331/xxx-xxx
  • 750-829
  • 750-882
  • 750-885

END UPDATE A

  • Firmware versions from FW1 to FW10 are affected.
  • All newer Firmware releases since FW11, released in December 2017, are not affected.

Summary

The Web-Based Management (WBM) of WAGOs programmable logic controller (PLC) is typically used for administration, commissioning and updates.
Older firmware versions of the PLC family 750-88x and 750-352 are vulnerable for a special denial of service attack.


Weakness

Uncontrolled Resource Consumption  (CWE-400) 

Summary

Older firmware versions (FW1 up to FW10) of the WAGO PLC family 750-88x and 750-352 are vulnerable for a special denial of service attack.


Impact

An attacker which sends a series of maliciously constructed packets to HTTP(S) ports 80/443 could cause a crashed device, that needs a power on reset to go back to normal operation.

Solution

Mitigation

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

Solution

Update the device to the latest FW version available here:

https://www.wago.com/us/requestDownload?downloadFile=FWMedia_58_750-881

Reported by

This vulnerability was reported to WAGO by William Knowles (Applied Risk)

CERT@VDE coordinated.