CVE-2020-7502Network attack vector

Controller crash via crafted TCP/IP packets

Published Jun 16, 2020 · Updated Aug 4, 2024

Out-of-bounds write in Distributed Data Systems Modicon M218 firmware 4.3 and earlier allows remote attackers to crash the controller. Specific crafted TCP/IP packets trigger the out-of-bounds write, but the vendor has not disclosed the affected parser or how bounds validation fails. No authentication or user interaction is required, and the reported consequence is limited to loss of controller availability.

CVSS severity7.5
High
EPSS probability1.52%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Out-of-bounds write in Distributed Data Systems Modicon M218 firmware 4.3 and earlier allows remote attackers to crash the controller. Specific crafted TCP/IP packets trigger the out-of-bounds write, but the vendor has not disclosed the affected parser or how bounds validation fails. No authentication or user interaction is required, and the reported consequence is limited to loss of controller availability.

The record

CVE
CVE-2020-7502
Published
Jun 16, 2020
Updated
Aug 4, 2024
Vendor
Distributed Data Systems
Product
Modicon M218 Logic Controller
Classifications
CWE-787, T1499.004
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Jun 16, 2020CVE publishedPublication date reported by the CVE source.
  2. Aug 4, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=Modicon M218 Logic Controller (Firmware version 4.3 and prior)

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Distributed Data Systems · Modicon M218 Logic Controllerversion=Modicon M218 Logic Controller (Firmware version 4.3 and prior)

Published CVSS scores

5.0NIST NVDAV:N/AC:L/Au:N/C:N/I:N/A:P
7.5NIST NVDCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-787Out-of-bounds Write
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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