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CVE-2019-18858· NVD / CVE Program· CNA mitre

CODESYS 3 web server before 3.5.15.20, as distributed with CODESYS Control runtime systems, has a Buffer Overflow.

Noroxi assessment

Priority: Plan (action score 40/100)

  • 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: 1.9% (FIRST EPSS); higher than 79.8% 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.

Add it to your regular patch cycle. 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

Primary sources: NVD · CVE.org · FIRST EPSS

CriticalCVSS 9.8 · v3.1—No exploit No fix recorded
Published
Nov 20, 2019
Updated
Jun 16, 2026
EPSS
1.9% · 79th percentile

Report tools

JSON

Action score

40

Plan

Add it to your regular patch cycle.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 1.9%

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

If any of these changes, we'll tell you in the daily email digest.

Follow CVE-2019-18858

When you'll hear from us

  • when it enters CISA KEV
  • when exploit code appears or is weaponized
  • when the record is updated (including a fixed version)
  • when EPSS rises 20 points in a week

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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.

VendorProduct
codesyscontrol for beaglebone
codesyscontrol for empc-a\/imx6
codesyscontrol for iot2000
codesyscontrol for linux
codesyscontrol for pfc100
codesyscontrol for pfc200
codesyscontrol for plcnext
codesyscontrol for raspberry pi
codesyscontrol rte
codesyscontrol runtime system toolkit
codesyscontrol win
codesysembedded target visu toolkit

and 2 more

Affected versions

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

  • codesys control for beaglebonebefore 3.5.15.20
  • codesys control for empc-a/imx6before 3.5.15.20
  • codesys control for iot2000before 3.5.15.20
  • codesys control for linuxbefore 3.5.15.20
  • codesys control for pfc100before 3.5.15.20
  • codesys control for pfc200before 3.5.15.20
  • codesys control for plcnextbefore 3.5.15.20
  • codesys control for raspberry pibefore 3.5.15.20
  • codesys control rtebefore 3.5.15.20
  • codesys control runtime system toolkitbefore 3.5.15.20
  • codesys control winbefore 3.5.15.20
  • codesys embedded target visu toolkitbefore 3.5.15.20
  • codesys hmibefore 3.5.15.20
  • codesys remote target visu toolkitbefore 3.5.15.20

Same product

codesys: all records

Other highest-scoring records for the same primary product.

  • CVE-2019-13548CODESYS V3 web server, all versions prior to 3.5.14.10, allows an attacker to send specially crafted http or https requests which could caus
    41Plan
  • CVE-2020-10245CODESYS V3 web server before 3.5.15.40, as used in CODESYS Control runtime systems, has a buffer overflow.
    40Plan
  • CVE-2019-9008An issue was discovered in 3S-Smart CODESYS V3 through 3.5.12.30.
    36Monitor
  • CVE-2018-25048Codesys Runtime Improper Limitation of a Pathname
    35Monitor
  • CVE-2020-12069CODESYS V3 prone to Inadequate Password Hashing
    31Monitor
  • CVE-2020-15806CODESYS Control runtime system before 3.5.16.10 allows Uncontrolled Memory Allocation.
    31Monitor

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.

—

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
high · data can be read
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
High
Integrity impact
High
Availability impact
High

Weakness class (CWE)

CWE-120 · Buffer Copy without Checking Size of Input ('Classic Buffer Overflow')

CVSS vector

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

nvd-primary

Root cause

When data is copied, the source length is not compared with the size of the destination buffer. Excess data overwrites adjacent memory.

The bug in code

The whole CWE-120 class

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

Vulnerable

c
char buf[256];memcpy(buf, pkt->data, pkt->len);

Fixed

c
char buf[256];if (pkt->len > sizeof(buf)) {  return -EINVAL;}memcpy(buf, pkt->data, pkt->len);

Attack context

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

ATT&CK techniques

—

Change log

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

References

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

All records