An exploitable heap buffer overflow vulnerability exists in the iocheckd service I/O-Check functionality of WAGO PFC200 Firmware version 03…

published 2020-01-08 6 y ago modified 2026-06-17 4 mo ago also EUVD-2019-14687

cvss: 9.8; version 3.1, NVD
cisa kev: Not listed; not in CISA's catalog
epss: 3.3%; EPSS 3.3% chance of exploitation in 30 days, percentile 88%
public exploits: 0; none known

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.

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 2020-03-05 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

3.32% chance of exploitation in the next 30 days, higher than 88% of all scored CVEs (FIRST EPSS, 2026-11-08).

Exploits and checks

talosintelligence.com https://talosintelligence.com/vulnerability_reports/TALOS-2019-0874 referenced PoC, tagged "exploit" by a source, unverified

CVSS scores

assigned by	version	score	vector
NVD	3.1	9.8	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
NVD	2.0	7.5	AV:N/AC:L/Au:N/C:P/I:P/A:P

Affected products

n/a WAGO PFC200
n/a WAGO PFC100

Classification

Weakness

CWE-787 Out-of-bounds Write

References

talosintelligence.com /vulnerability_reports/TALOS-2019-0874
exploit, third-party-advisory

Sources

CVE List CVE-2019-5082
NVD CVE-2019-5082

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.

Summary