CVE-2019-5078· NVD / CVE Program· CNA talos

An exploitable denial of service vulnerability exists in the iocheckd service "I/O-Check" functionality of WAGO PFC200 Firmware versions 03.

Noroxi assessment

Priority: Monitor (action score 36/100)

The sources we track (CISA KEV, Exploit-DB, Metasploit, Nuclei, GitHub) show no public exploit code or exploitation in the wild.
Probability of exploitation in the next 30 days: 1.6% (FIRST EPSS); higher than 75.9% of all records.
Anyone who can reach it over the internet can trigger it. No account or password is required. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.

Low priority for now. Update when a fix is released; follow the vendor's advisory.

Generated automatically from the record's data: CVSS (NVD and CNA), CISA KEV and SSVC, FIRST EPSS, exploit sources, fixed versions. How we calculate it

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.

CriticalCVSS 9.1 · v3.1—No exploit No fix recorded

Published: Dec 18, 2019
Updated: Jun 16, 2026
EPSS: 1.7% · 76th percentile
CWE: CWE-306

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 36 / 40 · 9.1 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.7%

Get told when this record changes

Not in KEV: no record of exploitation in the wild
No public exploit code on record
No fixed version yet

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Noroxi analysis

What does it mean in your environment?

The assessment above is generated automatically from the record's data; it doesn't know your environment. Our team verifies on your systems whether this vulnerability is actually exploitable and which mitigation is enough.

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Affected systems

Is your version affected?

Pick the product and type the version you run. It's compared with this record's version ranges in your browser; the version isn't sent anywhere.

Vendor	Product	CPE
wago	pfc 200 firmware	cpe:2.3:o:wago:pfc_200_firmware
wago	pfc 200	cpe:2.3:h:wago:pfc_200
wago	pfc 100 firmware	cpe:2.3:o:wago:pfc_100_firmware
wago	pfc 100	cpe:2.3:h:wago:pfc_100

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

wago pfc 100 firmware03.00.39(12)
wago pfc 200 firmware03.00.39(12)
wago pfc 200 firmware03.01.07(13)

Versions reported by the vendor

Affected version ranges reported by the assigning authority (talos). Independent of NVD's CPE analysis and usually ahead of it.

n/a WAGO PFC100
- Firmware version 03.00.39(12)affected
n/a WAGO PFC200
- Firmware version 03.01.07(13), Firmware version 03.00.39(12)affected

Same product

wago: all records

Other highest-scoring records for the same primary product.

CVE-2019-5079An exploitable heap buffer overflow vulnerability exists in the iocheckd service "I/O-Check" functionality of WAGO PFC200 Firmware versions
40Plan
CVE-2019-5075An exploitable stack buffer overflow vulnerability exists in the command line utility getcouplerdetails of WAGO PFC200 Firmware versions 03.
40Plan
CVE-2019-5081An exploitable heap buffer overflow vulnerability exists in the iocheckd service ''I/O-Chec'' functionality of WAGO PFC 200 Firmware version
40Plan
CVE-2019-5074An exploitable stack buffer overflow vulnerability exists in the iocheckd service ''I/O-Check'' functionality of WAGO PFC200 Firmware versio
40Plan
CVE-2019-5080An exploitable denial-of-service vulnerability exists in the iocheckd service "I/O-Check" functionality of WAGO PFC 200 Firmware versions 03
36Monitor
CVE-2019-5077An exploitable denial-of-service vulnerability exists in the iocheckd service ‘’I/O-Chec’’ functionality of WAGO PFC 200 Firmware versions 0
36Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

No fix version is recorded for this entry. Check the references for vendor advisories.

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Credits

All researchers

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

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Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
No account or password is required.
No user action is required.
No special conditions are required; it is repeatable.

If successful

Confidentiality: none
Integrity: high · data or configuration can be modified
Availability: high · the service can be disrupted

Attack vector: Network
Attack complexity: Low
Privileges required: None
User interaction: None
Scope: Unchanged
Confidentiality impact: None
Integrity impact: High
Availability impact: High

Weakness class (CWE)

CWE-306 · Missing Authentication for Critical Function

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:H

nvd-primary

Root cause

A function added for development or support ships to production without authentication. It often relies on the assumption that it is “only reachable from the internal network.”

The bug in code

The whole CWE-306 class

A representative example of this vulnerability class. Not the vendor's source code; it shows the faulty pattern and its fix.

Vulnerable

1// Added for the support team2app.post("/maintenance/reset", resetDevice);

Fixed

1if (config.maintenanceEnabled) {2  app.post(3    "/maintenance/reset",4    requireSession, requireRole("admin"), resetDevice5  );6}

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Attack patterns (CAPEC)

ATT&CK techniques

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Change log

No changes recorded on tracked fields yet. Score, KEV, exploit maturity and fix status changes appear here.

References

talosintelligence.com/vulnerability_reports/TALOS-2019-0870

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

All records