# CVE-2019-6855: Auth bypass in EcoStruxure Control Expert (all versions prior to 14.1 Hot Fix), Unity Pro (all versions), Modicon M340 (all versions prior to V3.20) , and Modicon M580 (all versions prior to V3.10) > Attackers can bypass authentication between EcoStruxure Control Expert and Modicon controllers, allowing unauthorized access to industrial control systems. - **Severity:** High 7.3 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L`) - **Exploited in the wild:** Not known - **Login needed:** Not needed - **Attackable:** Over the internet - **Victim action needed:** Not needed - **Fix available:** No - **Published:** 6 Jan 2020 - **Updated:** 4 Aug 2024 - **Also known as:** GHSA-f79p-hq3g-prjw ## What is CVE-2019-6855? CVE-2019-6855 is a high-severity authentication bypass vulnerability in EcoStruxure Control Expert (all versions prior to 14.1 Hot Fix), Unity Pro (all versions), Modicon M340 (all versions prior to V3.20) , and Modicon M580 (all versions prior to V3.10), published on 6 Jan 2020. An attacker can exploit it over the internet without logging in, with no action from the victim. ### Official description Incorrect Authorization vulnerability exists in EcoStruxure Control Expert (all versions prior to 14.1 Hot Fix), Unity Pro (all versions), Modicon M340 (all versions prior to V3.20) , and Modicon M580 (all versions prior to V3.10), which could cause a bypass of the authentication process between EcoStruxure Control Expert and the M340 and M580 controllers. Weakness: CWE-863 (Incorrect Authorization) ## Which versions are affected by CVE-2019-6855? It affects 23 products. Products: Schneider-Electric Ecostruxure Control Expert, Schneider-Electric Modicon M340 Bmxp341000 Firmware, Schneider-Electric Modicon M340 Bmxp342000 Firmware, Schneider-Electric Modicon M340 Bmxp3420102 Firmware, Schneider-Electric Modicon M340 Bmxp342020 Firmware, Schneider-Electric Modicon M340 Bmxp3420302 Firmware, Schneider-Electric Modicon M580 Bmeh582040 Firmware, Schneider-Electric Modicon M580 Bmeh584040 Firmware, Schneider-Electric Modicon M580 Bmeh584040s Firmware, Schneider-Electric Modicon M580 Bmeh586040 Firmware, Schneider-Electric Modicon M580 Bmeh586040s Firmware, Schneider-Electric Modicon M580 Bmep581020 Firmware, Schneider-Electric Modicon M580 Bmep582020 Firmware, Schneider-Electric Modicon M580 Bmep582040 Firmware, Schneider-Electric Modicon M580 Bmep582040s Firmware, Schneider-Electric Modicon M580 Bmep583020 Firmware, Schneider-Electric Modicon M580 Bmep583040 Firmware, Schneider-Electric Modicon M580 Bmep584020 Firmware, Schneider-Electric Modicon M580 Bmep584040 Firmware, Schneider-Electric Modicon M580 Bmep584040s Firmware and 3 more. ## How do I fix CVE-2019-6855? No fix has been published for CVE-2019-6855 yet. Limit exposure of the affected software until one is available. ## Is CVE-2019-6855 being exploited? There is no known exploitation of CVE-2019-6855 in the wild and no public exploit code. ## Other vulnerabilities in EcoStruxure Control Expert (all versions prior to 14.1 Hot Fix), Unity Pro (all versions), Modicon M340 (all versions prior to V3.20) , and Modicon M580 (all versions prior to V3.10) - [CVE-2022-37300](https://insights.sbomify.com/CVE-2022-37300/): Auth bypass in EcoStruxure Control Expert (critical 9.8) - [CVE-2020-28212](https://insights.sbomify.com/CVE-2020-28212/): Auth bypass in PLC Simulator on EcoStruxureª Control Expert (now Unity Pro) (all versions) (critical 9.8) - [CVE-2020-7475](https://insights.sbomify.com/CVE-2020-7475/): Code injection in EcoStruxure Control Expert (all versions prior to 14.1 Hot Fix), Unity Pro (all versions), Modicon M340 (all versions prior to V3.20), Modicon M580 (all versions prior to V3.10) (critical 9.8) - [CVE-2023-27976](https://insights.sbomify.com/CVE-2023-27976/): Other in EcoStruxure Control Expert (high 8.8) - [CVE-2020-28213](https://insights.sbomify.com/CVE-2020-28213/): Code injection in PLC Simulator on EcoStruxureª Control Expert (now Unity Pro) (all versions) (high 8.8) ## Fix prompt for AI coding agents ```text Check this codebase for CVE-2019-6855 and fix it if it is affected. What it is: CVE-2019-6855 is a high-severity authentication bypass vulnerability in EcoStruxure Control Expert (all versions prior to 14.1 Hot Fix), Unity Pro (all versions), Modicon M340 (all versions prior to V3.20) , and Modicon M580 (all versions prior to V3.10), published on 6 Jan 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-2019-6855 in the wild and no public exploit code. Affected product: EcoStruxure Control Expert (all versions prior to 14.1 Hot Fix), Unity Pro (all versions), Modicon M340 (all versions prior to V3.20) , and Modicon M580 (all versions prior to V3.10). 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-2019-6855/ (Markdown: https://insights.sbomify.com/CVE-2019-6855/index.md) ``` ## Sources - CVE record: https://www.cve.org/CVERecord?id=CVE-2019-6855 - NVD: https://nvd.nist.gov/vuln/detail/CVE-2019-6855 - OSV: https://osv.dev/vulnerability/CVE-2019-6855 --- From sbomify Insights: https://insights.sbomify.com/CVE-2019-6855/ Summaries are generated and may contain mistakes; the official description above is the record.