{"answers":{"affected":"It affects 4 products.","exploited":"There is no known exploitation of CVE-2021-25663 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2021-25663 yet. Limit exposure of the affected software until one is available.","what":"CVE-2021-25663 is a high-severity denial of service vulnerability in Siemens Capital Embedded AR Classic 431-422, published on 22 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim."},"fix_prompt":"Check this codebase for CVE-2021-25663 and fix it if it is affected.\n\nWhat it is: CVE-2021-25663 is a high-severity denial of service vulnerability in Siemens Capital Embedded AR Classic 431-422, published on 22 Apr 2021. An attacker can exploit it over the internet without logging in, with no action from the victim.\nExploitation: There is no known exploitation of CVE-2021-25663 in the wild and no public exploit code.\n\nAffected product: Siemens Capital Embedded AR Classic 431-422. 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-2021-25663/ (Markdown: https://insights.sbomify.com/CVE-2021-25663/index.md)","id":"CVE-2021-25663","markdown":"https://insights.sbomify.com/CVE-2021-25663/index.md","name":"CVE-2021-25663","record":{"aliases":["GHSA-m3qf-xv59-6w6h"],"analysis":{"component_type":"operating_system","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Siemens Nucleus RTOS","requires_auth":"none","summary":"Attackers can cause a denial of service in Siemens Nucleus RTOS products by sending crafted IPv6 headers that trigger an infinite loop.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"siemens","cpe":[{"product":"capital_vstar","vendor":"siemens"},{"product":"nucleus_net","vendor":"siemens"},{"product":"nucleus_readystart","vendor":"siemens"},{"product":"nucleus_source_code","vendor":"siemens"}],"cvss":{"score":8.7,"severity":"high","source":"cna","vector":"CVSS:4.0/AV:N/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-835","name":"Loop with Unreachable Exit Condition"}],"description":"A vulnerability has been identified in Capital Embedded AR Classic 431-422 (All versions), Capital Embedded AR Classic R20-11 (All versions \u003c V2303), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions \u003c V2017.02.4), Nucleus ReadyStart V4 (All versions \u003c V4.1.0), Nucleus Source Code (All versions including affected IPv6 stack). The function that processes IPv6 headers does not check the lengths of extension header options, allowing attackers to put this function into an infinite loop with crafted length values.","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 Capital Embedded AR Classic 431-422","id":"CVE-2021-25663","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2021"},"n_packages":0,"n_references":3,"next":{"headline":"Denial of service in Capital Embedded AR Classic 431-422","id":"CVE-2021-25664"},"packages":[],"prev":{"headline":"Denial of service in SIMATIC HMI Comfort Outdoor Panels V15 7\\\" \u0026 15\\\" (incl. SIPLUS variants)","id":"CVE-2021-25662"},"products":["Capital Embedded AR Classic 431-422","Capital Embedded AR Classic R20-11","Nucleus NET","Nucleus ReadyStart V3","Nucleus ReadyStart V4","Nucleus Source Code"],"published":"2021-04-22","related":[{"cvss_score":8.7,"headline":"Denial of service in Capital Embedded AR Classic 431-422","id":"CVE-2021-25664","kev_date_added":null,"published":"2021-04-22"},{"cvss_score":6.5,"headline":"Weak cryptography in APOGEE PXC Compact (BACnet)","id":"CVE-2020-28388","kev_date_added":null,"published":"2021-02-09"}],"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":null,"exploitation":null,"technical_impact":null},"state":"PUBLISHED","updated":"2025-03-11","vendors":["Siemens"]},"summary":"Attackers can cause a denial of service in Siemens Nucleus RTOS products by sending crafted IPv6 headers that trigger an infinite loop.","url":"https://insights.sbomify.com/CVE-2021-25663/"}