# CVE-2020-7477: Denial of service in Modicon Quantum Ethernet Network module and Quantum / Premium COPRO (Quantum Ethernet Network module 140NOE771x1, versions 7.0 and prior, Quantum processors with integrated Ethernet – 140CPU65xxxxx, all versions, Premium processors with integrated Ethernet, all versions) > Attackers can cause a denial of service on Schneider Electric Modicon Quantum and Premium processors by sending specially crafted Modbus commands. - **Severity:** High 7.5 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 23 Mar 2020 - **Updated:** 28 May 2026 - **Also known as:** GHSA-pf3g-p3qp-7mc8 ## What is CVE-2020-7477? CVE-2020-7477 is a high-severity denial of service vulnerability in Modicon Quantum Ethernet Network module and Quantum / Premium COPRO (Quantum Ethernet Network module 140NOE771x1, versions 7.0 and prior, Quantum processors with integrated Ethernet – 140CPU65xxxxx, all versions, Premium processors with integrated Ethernet, all versions), published on 23 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description A CWE-754: Improper Check for Unusual or Exceptional Conditions vulnerability exists in Quantum Ethernet Network module 140NOE771x1 (Versions 7.0 and prior), Quantum processors with integrated Ethernet – 140CPU65xxxxx (all Versions), and Premium processors with integrated Ethernet (all Versions), which could cause a Denial of Service when sending a specially crafted command over Modbus. Weakness: CWE-754 (Improper Check for Unusual or Exceptional Conditions) ## Which versions are affected by CVE-2020-7477? It affects 28 products. Products: Schneider-Electric 140cpu65150 Firmware, Schneider-Electric 140cpu65160 Firmware, Schneider-Electric 140cpu65160s Firmware, Schneider-Electric 140cpu65260 Firmware, Schneider-Electric 140cpu65860 Firmware, Schneider-Electric 140cpu67060 Firmware, Schneider-Electric 140cpu67160 Firmware, Schneider-Electric 140cpu67160s Firmware, Schneider-Electric 140cpu67260 Firmware, Schneider-Electric 140cpu67261 Firmware, Schneider-Electric 140cpu67861 Firmware, Schneider-Electric 140noe77101 Firmware, Schneider-Electric 140noe77111 Firmware, Schneider-Electric Tsxh5724m Firmware, Schneider-Electric Tsxh5744m Firmware, Schneider-Electric Tsxp57104m Firmware, Schneider-Electric Tsxp57154m Firmware, Schneider-Electric Tsxp571634m Firmware, Schneider-Electric Tsxp57204m Firmware, Schneider-Electric Tsxp57254m Firmware and 8 more. ## How do I fix CVE-2020-7477? No fix has been published for CVE-2020-7477 yet. Limit exposure of the affected software until one is available. ## Is CVE-2020-7477 being exploited? There is no known exploitation of CVE-2020-7477 in the wild and no public exploit code. ## Other vulnerabilities in Modicon Quantum Ethernet Network module and Quantum / Premium COPRO (Quantum Ethernet Network module 140NOE771x1, versions 7.0 and prior, Quantum processors with integrated Ethernet – 140CPU65xxxxx, all versions, Premium processors with integrated Ethernet, all versions) - [CVE-2020-7540](https://insights.sbomify.com/CVE-2020-7540/): Missing authorization in Web Server on Modicon M340, Legacy Offers Modicon Quantum and Modicon Premium and associated Communication Modules (see security notification for affected versions) (critical 9.8) - [CVE-2021-22785](https://insights.sbomify.com/CVE-2021-22785/): Information disclosure in Modicon M340 CPUs: BMXP34 (Versions prior to V3.40), Modicon M340 X80 Ethernet Communication Modules: BMXNOE0100 (H), BMXNOE0110 (H), BMXNOC0401, BMXNOR0200H RTU (All Versions), Modicon Premium Processors with integrated Ethernet (Copro): TSXP574634, TSXP575634, TSXP576634 (All Versions), Modicon Quantum Processors with Integrated Ethernet (Copro): 140CPU65xxxxx (All Versions), Modicon Quantum Communication Modules: 140NOE771x1, 140NOC78x00, 140NOC77101 (All Versions), Modicon Premium Communication Modules: TSXETY4103, TSXETY5103 (All Versions) (high 7.5) - [CVE-2021-22787](https://insights.sbomify.com/CVE-2021-22787/): Denial of service in Modicon M340 CPUs: BMXP34 (Versions prior to V3.40), Modicon M340 X80 Ethernet Communication Modules: BMXNOE0100 (H), BMXNOE0110 (H), BMXNOC0401, BMXNOR0200H RTU (All Versions), Modicon Premium Processors with integrated Ethernet (Copro): TSXP574634, TSXP575634, TSXP576634 (All Versions), Modicon Quantum Processors with Integrated Ethernet (Copro): 140CPU65xxxxx (All Versions), Modicon Quantum Communication Modules: 140NOE771x1, 140NOC78x00, 140NOC77101 (All Versions), Modicon Premium Communication Modules: TSXETY4103, TSXETY5103 (All Versions) (high 7.5) - [CVE-2021-22788](https://insights.sbomify.com/CVE-2021-22788/): Memory corruption in Modicon M340 CPUs: BMXP34 (Versions prior to V3.40), Modicon M340 X80 Ethernet Communication Modules: BMXNOE0100 (H), BMXNOE0110 (H), BMXNOC0401, BMXNOR0200H RTU (All Versions), Modicon Premium Processors with integrated Ethernet (Copro): TSXP574634, TSXP575634, TSXP576634 (All Versions), Modicon Quantum Processors with Integrated Ethernet (Copro): 140CPU65xxxxx (All Versions), Modicon Quantum Communication Modules: 140NOE771x1, 140NOC78x00, 140NOC77101 (All Versions), Modicon Premium Communication Modules: TSXETY4103, TSXETY5103 (All Versions) (high 7.5) - [CVE-2020-7535](https://insights.sbomify.com/CVE-2020-7535/): Path traversal in Web Server on Modicon M340, Legacy Offers Modicon Quantum and Modicon Premium and associated Communication Modules (see security notification for affected versions) (high 7.5) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2020-7477 and fix it if it is affected. What it is: CVE-2020-7477 is a high-severity denial of service vulnerability in Modicon Quantum Ethernet Network module and Quantum / Premium COPRO (Quantum Ethernet Network module 140NOE771x1, versions 7.0 and prior, Quantum processors with integrated Ethernet – 140CPU65xxxxx, all versions, Premium processors with integrated Ethernet, all versions), published on 23 Mar 2020. An attacker can exploit it over the internet without logging in, with no action from the victim. Exploitation: There is no known exploitation of CVE-2020-7477 in the wild and no public exploit code. Affected product: Modicon Quantum Ethernet Network module and Quantum / Premium COPRO (Quantum Ethernet Network module 140NOE771x1, versions 7.0 and prior, Quantum processors with integrated Ethernet – 140CPU65xxxxx, all versions, Premium processors with integrated Ethernet, all versions). No package-level version data is available, so check the vendor advisory linked from the reference page. Task: 1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies. 2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it. 3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead. 4. Run the tests and summarise what changed and why. 5. If nothing in the project is affected, say so and change nothing. Reference: https://insights.sbomify.com/CVE-2020-7477/ (Markdown: https://insights.sbomify.com/CVE-2020-7477/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2020-7477 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2020-7477 - OSV: https://osv.dev/vulnerability/CVE-2020-7477 --- From sbomify Insights: https://insights.sbomify.com/CVE-2020-7477/ Summaries are generated and may contain mistakes; the official description above is the record.