{"answers":{"affected":"It affects 1 product.","exploited":"There is no known exploitation of CVE-2021-34432 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2021-34432 is a high-severity denial of service vulnerability in The Eclipse Foundation Eclipse Mosquitto, published on 27 Jul 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-2021-34432 and fix it if it is affected.\n\nWhat it is: CVE-2021-34432 is a high-severity denial of service vulnerability in The Eclipse Foundation Eclipse Mosquitto, published on 27 Jul 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-2021-34432 in the wild and no public exploit code.\n\nAffected product: The Eclipse Foundation Eclipse Mosquitto. 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-2021-34432/ (Markdown: https://insights.sbomify.com/CVE-2021-34432/index.md)","id":"CVE-2021-34432","markdown":"https://insights.sbomify.com/CVE-2021-34432/index.md","name":"CVE-2021-34432","record":{"aliases":["ALPINE-CVE-2021-34432","DEBIAN-CVE-2021-34432","GHSA-9972-xmxv-v66x","OESA-2022-1564","OESA-2022-2053"],"analysis":{"component_type":"server_software","fix_type":"upgrade","impacts":["denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"MQTT broker","requires_auth":"none","summary":"A remote attacker can crash the Eclipse Mosquitto MQTT broker by sending a PUBLISH packet with a zero-length topic.","user_interaction":"not_required","vuln_class":"denial_of_service"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"eclipse","cpe":[{"product":"mosquitto","vendor":"eclipse"}],"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-20","name":"Improper Input Validation"}],"description":"In Eclipse Mosquitto versions 2.0.7 and earlier, the server will crash if the client tries to send a PUBLISH packet with topic length = 0.","ecosystems":[],"exploits":{"exploitdb":0,"first_seen":null,"github_poc":0,"max_poc_stars":null,"metasploit":0,"nuclei":0,"refs":[],"tier":"none_known"},"has_fix":true,"headline":"Denial of service in Eclipse Mosquitto","id":"CVE-2021-34432","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":"Auth bypass in Eclipse Californium","id":"CVE-2021-34433"},"packages":[],"prev":{"headline":"Denial of service in Eclipse Mosquitto","id":"CVE-2021-34431"},"products":["Eclipse Mosquitto"],"published":"2021-07-27","related":[{"cvss_score":8.1,"headline":"Auth bypass in Eclipse Mosquitto","id":"CVE-2018-12550","kev_date_added":null,"published":"2019-03-27"},{"cvss_score":8.1,"headline":"Auth bypass in Eclipse Mosquitto","id":"CVE-2018-12551","kev_date_added":null,"published":"2019-03-27"},{"cvss_score":7.5,"headline":"Unconditionally adding an event to the epoll causes excessive CPU consumption","id":"CVE-2023-5632","kev_date_added":null,"published":"2023-10-18"},{"cvss_score":7.5,"headline":"Denial of service in n/a","id":"CVE-2023-28366","kev_date_added":null,"published":"2023-09-01"},{"cvss_score":7.5,"headline":"Denial of service in Eclipse Mosquitto","id":"CVE-2021-41039","kev_date_added":null,"published":"2021-12-01"},{"cvss_score":7.5,"headline":"Missing authorization in n/a","id":"CVE-2018-20145","kev_date_added":null,"published":"2018-12-13"}],"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":"2026-07-02","vendors":["The Eclipse Foundation"]},"summary":"A remote attacker can crash the Eclipse Mosquitto MQTT broker by sending a PUBLISH packet with a zero-length topic.","url":"https://insights.sbomify.com/CVE-2021-34432/"}