Skip to content
Noroxi
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

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
Published
Nov 18, 2020
Updated
Jun 16, 2026
EPSS
1.1% · 65th percentile
Follow this CVE

Sign in to follow · You’ll be notified if a followed record enters KEV, gets an exploit or is updated.

Report tools

JSON

Action score

35

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.

Noroxi analysis

No Noroxi analysis for this record yet

We don't hand-write analysis for the hundreds of thousands of vulnerabilities in the database; that wouldn't be honest. For notable, high-impact vulnerabilities our team writes the mechanism, detection and remediation steps.

We use this product, ask for help

Affected systems

VendorProduct
schneider-electricmodicon tsxety4103 firmware
schneider-electricmodicon tsxety4103
schneider-electricmodicon tsxety5103 firmware
schneider-electricmodicon tsxety5103
schneider-electricmodicon tsxp574634 firmware
schneider-electricmodicon tsxp574634
schneider-electricmodicon tsxp575634 firmware
schneider-electricmodicon tsxp575634
schneider-electricmodicon tsxp576634 firmware
schneider-electricmodicon tsxp576634
schneider-electricmodicon quantum 140noe77101 firmware
schneider-electricmodicon 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).

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

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