{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-40523 in the wild and no public exploit code.","fix":"No fix has been published for CVE-2021-40523 yet. Limit exposure of the affected software until one is available.","what":"CVE-2021-40523 is a high-severity denial of service vulnerability in n/a, published on 5 Sep 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-2021-40523 and fix it if it is affected.\n\nWhat it is: CVE-2021-40523 is a high-severity denial of service vulnerability in n/a, published on 5 Sep 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-2021-40523 in the wild and no public exploit code.\n\nAffected product: n/a. 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-2021-40523/ (Markdown: https://insights.sbomify.com/CVE-2021-40523/index.md)","id":"CVE-2021-40523","markdown":"https://insights.sbomify.com/CVE-2021-40523/index.md","name":"CVE-2021-40523","record":{"aliases":["GHSA-9rqj-h33r-qgm8"],"analysis":{"component_type":"iot_embedded","fix_type":"patch","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"Contiki OS","requires_auth":"none","summary":"A flaw in Contiki OS Telnet negotiation handling can cause a denial of service by exhausting response buffers.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"mitre","cpe":[{"product":"contiki","vendor":"contiki-os"}],"cvss":{"score":7.5,"severity":"high","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","version":"3.1"},"cwes":[{"id":"CWE-754","name":"Improper Check for Unusual or Exceptional Conditions"}],"description":"In Contiki 3.0, Telnet option negotiation is mishandled. During negotiation between a server and a client, the server may fail to give the WILL/WONT or DO/DONT response for DO and WILL commands because of improper handling of exception condition, which leads to property violations and denial of service. Specifically, a server sometimes sends no response, because a fixed buffer space is available for all responses and that space may have been exhausted.","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 n/a","id":"CVE-2021-40523","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":null,"products":[],"type":"denial_of_service","year":"2021"},"n_packages":0,"n_references":1,"next":{"headline":"Denial of service in n/a","id":"CVE-2021-40524"},"packages":[],"prev":{"headline":"Code injection in n/a","id":"CVE-2021-40521"},"products":["n/a"],"published":"2021-09-05","related":[{"cvss_score":7.5,"headline":"Memory corruption in n/a","id":"CVE-2021-38386","kev_date_added":null,"published":"2021-08-10"},{"cvss_score":7.5,"headline":"Denial of service in n/a","id":"CVE-2021-38387","kev_date_added":null,"published":"2021-08-10"},{"cvss_score":7.5,"headline":"Denial of service in n/a","id":"CVE-2021-38311","kev_date_added":null,"published":"2021-08-09"},{"cvss_score":7.5,"headline":"Integer overflow in n/a","id":"CVE-2021-28362","kev_date_added":null,"published":"2021-03-24"},{"cvss_score":7.5,"headline":"Denial of service in n/a","id":"CVE-2020-13984","kev_date_added":null,"published":"2020-12-11"},{"cvss_score":7.5,"headline":"Memory corruption in n/a","id":"CVE-2020-13985","kev_date_added":null,"published":"2020-12-11"}],"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":"2024-08-04","vendors":["n/a"]},"summary":"A flaw in Contiki OS Telnet negotiation handling can cause a denial of service by exhausting response buffers.","url":"https://insights.sbomify.com/CVE-2021-40523/"}