{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2025-40939 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2025-40939 yet. Limit exposure of the affected software until one is available.","what":"CVE-2025-40939 is a medium-severity denial of service vulnerability in Siemens SIMATIC CN 4100, published on 9 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2025-40939 and fix it if it is affected.\n\nWhat it is: CVE-2025-40939 is a medium-severity denial of service vulnerability in Siemens SIMATIC CN 4100, published on 9 Dec 2025. It can only be exploited from the same machine or local network, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2025-40939 in the wild and no public exploit code.\n\nAffected product: Siemens SIMATIC CN 4100. No package-level version data is available, so check the vendor advisory linked from the reference page.\n\nTask:\n1. 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.\n2. 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.\n3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.\n4. Run the tests and summarise what changed and why.\n5. If nothing in the project is affected, say so and change nothing.\n\nReference: https://insights.sbomify.com/CVE-2025-40939/ (Markdown: https://insights.sbomify.com/CVE-2025-40939/index.md)","id":"CVE-2025-40939","markdown":"https://insights.sbomify.com/CVE-2025-40939/index.md","name":"CVE-2025-40939","record":{"aliases":["GHSA-35wm-hq5r-2p36"],"analysis":{"component_type":"ics_ot","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"adjacent_or_local","non_default_config":false,"product_category":"Industrial network device","requires_auth":"none","summary":"An attacker with physical access can trigger a reboot via the USB port, causing a denial of service on the SIMATIC CN 4100.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"siemens","cpe":[{"product":"simatic_cn_4100_firmware","vendor":"siemens"}],"cvss":{"score":5.1,"severity":"medium","source":"cna","vector":"CVSS:4.0/AV:P/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N","version":"4.0"},"cwes":[{"id":"CWE-284","name":"Improper Access Control"}],"description":"A vulnerability has been identified in SIMATIC CN 4100 (All versions \u003c V4.0.1). The affected device contains a USB port which allows unauthenticated connections. This could allow an attacker with physical access to the device to trigger reboot that could cause denial of service condition.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":null,"headline":"Denial of service in SIMATIC CN 4100","id":"CVE-2025-40939","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2025"},"n_packages":0,"n_references":1,"next":{"headline":"Information disclosure in SIMATIC CN 4100","id":"CVE-2025-40940"},"packages":[],"prev":{"headline":"Hardcoded credentials in SIMATIC CN 4100","id":"CVE-2025-40938"},"products":["SIMATIC CN 4100"],"published":"2025-12-09","related":[{"cvss_score":10,"headline":"Hardcoded credentials in SIMATIC CN 4100","id":"CVE-2024-32741","kev_date_added":null,"published":"2024-05-14"},{"cvss_score":9.9,"headline":"Privilege escalation in SIMATIC CN 4100","id":"CVE-2023-29130","kev_date_added":null,"published":"2023-07-11"},{"cvss_score":9.8,"headline":"Hardcoded credentials in SIMATIC CN 4100","id":"CVE-2024-32740","kev_date_added":null,"published":"2024-05-14"},{"cvss_score":9.8,"headline":"Hardcoded credentials in SIMATIC CN 4100","id":"CVE-2023-49621","kev_date_added":null,"published":"2024-01-09"},{"cvss_score":9.2,"headline":"Hardcoded credentials in SIMATIC CN 4100","id":"CVE-2025-40938","kev_date_added":null,"published":"2025-12-09"},{"cvss_score":8.8,"headline":"Missing authorization in SIMATIC CN 4100","id":"CVE-2026-22924","kev_date_added":null,"published":"2026-05-12"},{"cvss_score":8.8,"headline":"Auth bypass in SIMATIC CN 4100","id":"CVE-2023-49251","kev_date_added":null,"published":"2024-01-09"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"US public information, NVD API terms","name":"NVD"},{"class":"attribution","licence":"CWE Terms of Use","name":"CWE (MITRE)"},{"class":"attribution","licence":"FIRST CVSS licence","name":"CVSS (FIRST)"}],"ssvc":{"automatable":"no","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2025-12-09","vendors":["Siemens"]},"summary":"An attacker with physical access can trigger a reboot via the USB port, causing a denial of service on the SIMATIC CN 4100.","url":"https://insights.sbomify.com/CVE-2025-40939/"}