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Fencer Vulns
critical 9.1

CVE-2019-5077 json

An exploitable denial-of-service vulnerability exists in the iocheckd service ‘’I/O-Chec’’ functionality of WAGO PFC 200 Firmware versions…

published 2019-12-18 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-14682

cvss
9.1
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
1.6%
EPSS 1.6% chance of exploitation in 30 days, percentile 76%
public exploits
0
none known

Summary

An exploitable denial-of-service vulnerability exists in the iocheckd service ‘’I/O-Chec’’ functionality of WAGO PFC 200 Firmware versions 03.01.07(13) and 03.00.39(12), and WAGO PFC 100 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.

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

cisa ICSA-20-065-01 updated cvss 10.0

WAGO I/O-CHECK

  • WAGO I/O-CHECK Series PFC100 and Series PFC200 750-823, 750-832/xxx-xxx, 750-862, 750-890/xxx-xxx, 750-891, 750-852, 750-831/xxx-xxx, 750-881, 750-880/xxx-xxx, 750-889 WAGO Series PFC100 750-81xx/xxx-xxx WAGO Series PFC200 750-82xx/xxx-xxx
    affected: mitigation “WAGO recommends updating to the latest firmware, FW 15 or above. WAGO has identified the following specific workarounds and mitigations users can apply to reduce the risk:”

From CISA ICS and IT advisories (CSAF, https://github.com/cisagov/CSAF), a U.S. Government work; changed: reduced to products, statuses and remediations. CISA notification · csaf

Exploit prediction

1.64% chance of exploitation in the next 30 days, higher than 76% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H
NVD 2.0 8.5 AV:N/AC:L/Au:N/C:N/I:P/A:C

Affected products

  • n/a WAGO PFC200
  • n/a WAGO PFC100

Classification

Weakness
  • CWE-306 Missing Authentication for Critical Functionality

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.