CVE-2020-7564· NVD / CVE Program· CNA schneider

A CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability exists in the Web Server on Modicon M340, Mo

Noroxi assessment

Priority: Monitor (action score 35/100)

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: 1.1% (FIRST EPSS); higher than 66.4% of all records.
Anyone who can reach it over the internet can trigger it. A low-privileged account is enough. No user action is required. No special conditions are required; it is repeatable.
According to the record, no fixed version is available yet.
Mentioned 1 time in Turkish national cyber security advisories (siberguvenlik.gov.tr).

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

Primary sources: NVD · CVE.org · FIRST EPSS

A CWE-120: Buffer Copy without Checking Size of Input ('Classic Buffer Overflow') vulnerability exists in the Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details) which could cause write access and the execution of commands when uploading a specially crafted file on the controller over FTP.

HighCVSS 8.8 · v3.1—No exploit No fix recorded

Memory safety

BDU:2022-03130

Published: Nov 18, 2020
Updated: Jun 16, 2026
EPSS: 1.1% · 66th percentile
CWE: CWE-120

Report tools

JSON

Action score

Monitor

Low priority for now.

CVSS: 35 / 40 · 8.8 / 10
CISA KEV: 0 / 30 · Not listed
EPSS: 0 / 30 · 1.1%

CISA SSVC decision

Exploitation: none
Automatable: no
Technical impact: partial

Vulnrichment: CISA's decision-tree inputs.

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.

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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.

ProductVersion

Vendor	Product	CPE
schneider-electric	modicon tsxety4103 firmware	cpe:2.3:o:schneider-electric:modicon_tsxety4103_firmware
schneider-electric	modicon tsxety4103	cpe:2.3:h:schneider-electric:modicon_tsxety4103
schneider-electric	modicon tsxety5103 firmware	cpe:2.3:o:schneider-electric:modicon_tsxety5103_firmware
schneider-electric	modicon tsxety5103	cpe:2.3:h:schneider-electric:modicon_tsxety5103
schneider-electric	modicon tsxp574634 firmware	cpe:2.3:o:schneider-electric:modicon_tsxp574634_firmware
schneider-electric	modicon tsxp574634	cpe:2.3:h:schneider-electric:modicon_tsxp574634
schneider-electric	modicon tsxp575634 firmware	cpe:2.3:o:schneider-electric:modicon_tsxp575634_firmware
schneider-electric	modicon tsxp575634	cpe:2.3:h:schneider-electric:modicon_tsxp575634
schneider-electric	modicon tsxp576634 firmware	cpe:2.3:o:schneider-electric:modicon_tsxp576634_firmware
schneider-electric	modicon tsxp576634	cpe:2.3:h:schneider-electric:modicon_tsxp576634
schneider-electric	modicon quantum 140noe77101 firmware	cpe:2.3:o:schneider-electric:modicon_quantum_140noe77101_firmware
schneider-electric	modicon quantum 140noe77101	cpe:2.3:h:schneider-electric:modicon_quantum_140noe77101

and 28 more

Affected versions

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

schneider-electric modicon m340 bmx noc 0401 firmwareall versions
schneider-electric modicon m340 bmx noe 0100 firmwareall versions
schneider-electric modicon m340 bmx noe 0100h firmwareall versions
schneider-electric modicon m340 bmx noe 0110 firmwareall versions
schneider-electric modicon m340 bmx noe 0110h firmwareall versions
schneider-electric modicon m340 bmx nor 0200h firmwareall versions
schneider-electric modicon m340 bmx p34-2010 firmwareall versions
schneider-electric modicon m340 bmx p34-2030 firmwareall versions
schneider-electric modicon quantum 140cpu65150 firmwareall versions
schneider-electric modicon quantum 140cpu65150c firmwareall versions
schneider-electric modicon quantum 140cpu65160 firmwareall versions
schneider-electric modicon quantum 140cpu65160c firmwareall versions
schneider-electric modicon quantum 140noc78100 firmwareall versions
schneider-electric modicon quantum 140noe77101 firmwareall versions
schneider-electric modicon quantum 140noe77111 firmwareall versions
schneider-electric modicon tsxety4103 firmwareall versions
schneider-electric modicon tsxety5103 firmwareall versions
schneider-electric modicon tsxp574634 firmwareall versions
schneider-electric modicon tsxp575634 firmwareall versions
schneider-electric modicon tsxp576634 firmwareall versions

Versions reported by the vendor

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

n/a Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details)
- Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and their Communication Modules (see notification for details)affected

Same product

schneider-electric: all records

Other highest-scoring records for the same primary product.

CVE-2020-7563A CWE-787: Out-of-bounds Write vulnerability exists in the Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and
35Monitor
CVE-2020-7562A CWE-125: Out-of-Bounds Read vulnerability exists in the Web Server on Modicon M340, Modicon Quantum and Modicon Premium Legacy offers and
32Monitor

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).

National notice (Türkiye Cybersecurity Directorate / USOM)

Official security notices citing this record; remediation advice is on the agency's page.

TR-21-0014 · Jan 8, 2021(Schneider Electric Modicon M340 Zafiyeti)

All national notices →

Technical details

Attack conditions

Anyone who can reach it over the internet can trigger it.
A low-privileged account is enough.
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: Low
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:L/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

1char buf[256];
2memcpy(buf, pkt->data, pkt->len);

Fixed

1char buf[256];
2if (pkt->len > sizeof(buf)) {
3  return -EINVAL;
4}
5memcpy(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.

Attack patterns (CAPEC)

ATT&CK techniques

—

Change log

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

References

www.se.com/ww/en/download/document/SEVD-2020-315-01/

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

All records