{"answers":{"affected":"It affects 4 products.","exploited":"There is no known exploitation of CVE-2021-20236 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2021-20236 is a critical memory corruption vulnerability in Fedoraproject Fedora, published on 28 May 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-2021-20236 and fix it if it is affected.\n\nWhat it is: CVE-2021-20236 is a critical memory corruption vulnerability in Fedoraproject Fedora, published on 28 May 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-2021-20236 in the wild and no public exploit code.\n\nAffected product: Fedoraproject Fedora. 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-2021-20236/ (Markdown: https://insights.sbomify.com/CVE-2021-20236/index.md)","id":"CVE-2021-20236","markdown":"https://insights.sbomify.com/CVE-2021-20236/index.md","name":"CVE-2021-20236","record":{"aliases":["DEBIAN-CVE-2021-20236","GHSA-4j25-p3vq-p264","GHSA-qq65-x72m-9wr8","JLSEC-2026-516","UBUNTU-CVE-2021-20236"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["code_execution","denial_of_service"],"network_reachable":"yes","non_default_config":false,"product_category":"ZeroMQ messaging library","requires_auth":"none","summary":"A stack buffer overflow in ZeroMQ allows malicious clients to cause crashes or execute arbitrary code via crafted subscription requests.","user_interaction":"not_required","vuln_class":"memory_corruption"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"redhat","cpe":[{"product":"fedora","vendor":"fedoraproject"},{"product":"ceph_storage","vendor":"redhat"},{"product":"enterprise_linux","vendor":"redhat"},{"product":"zeromq","vendor":"zeromq"}],"cvss":{"score":9.8,"severity":"critical","source":"nvd","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","version":"3.1"},"cwes":[{"id":"CWE-787","name":"Out-of-bounds Write"},{"id":"CWE-120","name":"Buffer Copy without Checking Size of Input"}],"description":"A flaw was found in the ZeroMQ server in versions before 4.3.3. This flaw allows a malicious client to cause a stack buffer overflow on the server by sending crafted topic subscription requests and then unsubscribing. The highest threat from this vulnerability is to confidentiality, integrity, as well as system availability.","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":"Memory corruption in zeromq","id":"CVE-2021-20236","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":null,"product":"fedoraproject:fedora","products":["fedoraproject:fedora","redhat:enterprise_linux"],"type":"memory_corruption","year":"2021"},"n_packages":0,"n_references":2,"next":{"headline":"Denial of service in zeromq","id":"CVE-2021-20237"},"packages":[],"prev":{"headline":"Memory corruption in zeromq","id":"CVE-2021-20235"},"products":["zeromq"],"published":"2021-05-28","related":[{"cvss_score":9.8,"headline":"PHP-CGI OS Command Injection","id":"CVE-2024-4577","kev_date_added":"2024-06-12","published":"2024-06-09"},{"cvss_score":9.8,"headline":"Grafana Authentication Bypass","id":"CVE-2021-39226","kev_date_added":"2022-08-25","published":"2021-10-05"},{"cvss_score":9.8,"headline":"VMware ESXi and Horizon DaaS OpenSLP Heap-Based Buffer Overflow","id":"CVE-2019-5544","kev_date_added":"2021-11-03","published":"2019-12-06"},{"cvss_score":9.6,"headline":"Google Chromium V8 Type Confusion","id":"CVE-2024-4947","kev_date_added":"2024-05-20","published":"2024-05-15"},{"cvss_score":9.6,"headline":"Google Chromium Visuals Use-After-Free","id":"CVE-2024-4671","kev_date_added":"2024-05-13","published":"2024-05-09"},{"cvss_score":9.6,"headline":"Google Chromium Mojo Insufficient Data Validation","id":"CVE-2022-3075","kev_date_added":"2022-09-08","published":"2022-09-26"},{"cvss_score":9.6,"headline":"Google Chromium Indexed DB API Use-After-Free","id":"CVE-2021-30633","kev_date_added":"2021-11-03","published":"2021-10-08"}],"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":"2024-08-03","vendors":["n/a"]},"summary":"A stack buffer overflow in ZeroMQ allows malicious clients to cause crashes or execute arbitrary code via crafted subscription requests.","url":"https://insights.sbomify.com/CVE-2021-20236/"}