{"answers":{"affected":"6 open source packages ship an affected version, including io.netty:netty, io.netty:netty-codec-http2 and org.jboss.netty:netty. It affects 18 products.","exploited":"There is no known exploitation of CVE-2021-21409 in the wild and no public exploit code.","fix":"Upgrade to a fixed version.","what":"CVE-2021-21409 is a medium-severity vulnerability in Debian Debian Linux, published on 30 Mar 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-2021-21409 and fix it if it is affected.\n\nWhat it is: CVE-2021-21409 is a medium-severity vulnerability in Debian Debian Linux, published on 30 Mar 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-2021-21409 in the wild and no public exploit code.\n\nAffected packages and fixed versions:\n- io.netty:netty (Maven): affected all versions; no fix listed\n- io.netty:netty (Maven): affected all versions; no fix listed\n- io.netty:netty-codec-http2 (Maven): affected from 4.0.0; fixed in 4.1.61.Final\n- io.netty:netty-codec-http2 (Maven): affected from 4.0.0; fixed in 4.1.61.Final\n- org.jboss.netty:netty (Maven): affected all versions; no fix listed\n- org.jboss.netty:netty (Maven): affected all versions; no fix listed\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-2021-21409/ (Markdown: https://insights.sbomify.com/CVE-2021-21409/index.md)","id":"CVE-2021-21409","markdown":"https://insights.sbomify.com/CVE-2021-21409/index.md","name":"CVE-2021-21409","record":{"aliases":["CLEANSTART-2026-WI10177","CLEANSTART-2026-ZX30626","DEBIAN-CVE-2021-21409","GHSA-f256-j965-7f32","SUSE-SU-2022:1315-1","UBUNTU-CVE-2021-21409"],"analysis":{"component_type":"library","fix_type":"upgrade","impacts":["security_bypass"],"network_reachable":"yes","non_default_config":false,"product_category":"Netty HTTP/2 codec","requires_auth":"none","summary":"Attackers can perform HTTP request smuggling via Netty's HTTP/2 codec when content-length validation is missing, potentially bypassing security controls.","user_interaction":"not_required","vuln_class":"other"},"analysis_generated_by":"qwen3.8-flash-next","assigner":"GitHub_M","cpe":[{"product":"debian_linux","vendor":"debian"},{"product":"oncommand_api_services","vendor":"netapp"},{"product":"oncommand_workflow_automation","vendor":"netapp"},{"product":"netty","vendor":"netty"},{"product":"banking_corporate_lending_process_management","vendor":"oracle"},{"product":"banking_credit_facilities_process_management","vendor":"oracle"},{"product":"banking_trade_finance_process_management","vendor":"oracle"},{"product":"coherence","vendor":"oracle"},{"product":"communications_brm_-_elastic_charging_engine","vendor":"oracle"},{"product":"communications_cloud_native_core_console","vendor":"oracle"},{"product":"communications_cloud_native_core_policy","vendor":"oracle"},{"product":"communications_design_studio","vendor":"oracle"},{"product":"communications_messaging_server","vendor":"oracle"},{"product":"helidon","vendor":"oracle"},{"product":"jd_edwards_enterpriseone_tools","vendor":"oracle"},{"product":"nosql_database","vendor":"oracle"},{"product":"primavera_gateway","vendor":"oracle"},{"product":"quarkus","vendor":"quarkus"}],"cvss":{"score":5.9,"severity":"medium","source":"cna","vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N","version":"3.1"},"cwes":[{"id":"CWE-444","name":"Inconsistent Interpretation of HTTP Requests"}],"description":"Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers \u0026 clients. In Netty (io.netty:netty-codec-http2) before version 4.1.61.Final there is a vulnerability that enables request smuggling. The content-length header is not correctly validated if the request only uses a single Http2HeaderFrame with the endStream set to to true. This could lead to request smuggling if the request is proxied to a remote peer and translated to HTTP/1.1. This is a followup of GHSA-wm47-8v5p-wjpj/CVE-2021-21295 which did miss to fix this one case. This was fixed as part of 4.1.61.Final.","ecosystems":["Maven","openSUSE:Leap 15.3"],"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":"Possible request smuggling in HTTP/2 due missing validation of content-length","id":"CVE-2021-21409","indexable":true,"kev":null,"kind":"cve","links":{"ecosystem":"Maven","product":"debian:debian_linux","products":["debian:debian_linux","netapp:oncommand_workflow_automation","netty:netty","oracle:coherence","oracle:communications_cloud_native_core_policy","oracle:helidon","oracle:jd_edwards_enterpriseone_tools","oracle:primavera_gateway"],"type":"other","year":"2021"},"n_packages":7,"n_references":59,"next":{"headline":"Out-of-bounds read in the 6LoWPAN implementation","id":"CVE-2021-21410"},"packages":[{"ecosystem":"Maven","fixed":[],"introduced":["0"],"last_affected":[],"package":"io.netty:netty","purl":null,"source":"GHSA-f256-j965-7f32"},{"ecosystem":"Maven","fixed":[],"introduced":["0"],"last_affected":[],"package":"io.netty:netty","purl":"pkg:maven/io.netty/netty","source":"GHSA-f256-j965-7f32"},{"ecosystem":"Maven","fixed":["4.1.61.Final"],"introduced":["4.0.0"],"last_affected":[],"package":"io.netty:netty-codec-http2","purl":null,"source":"GHSA-f256-j965-7f32"},{"ecosystem":"Maven","fixed":["4.1.61.Final"],"introduced":["4.0.0"],"last_affected":[],"package":"io.netty:netty-codec-http2","purl":"pkg:maven/io.netty/netty-codec-http2","source":"GHSA-f256-j965-7f32"},{"ecosystem":"Maven","fixed":[],"introduced":["0"],"last_affected":[],"package":"org.jboss.netty:netty","purl":null,"source":"GHSA-f256-j965-7f32"},{"ecosystem":"Maven","fixed":[],"introduced":["0"],"last_affected":[],"package":"org.jboss.netty:netty","purl":"pkg:maven/org.jboss.netty/netty","source":"GHSA-f256-j965-7f32"},{"ecosystem":"openSUSE:Leap 15.3","fixed":["4.1.75-150200.4.9.1"],"introduced":["0"],"last_affected":[],"package":"netty","purl":"pkg:rpm/opensuse/netty\u0026distro=openSUSE%20Leap%2015.3","source":"SUSE-SU-2022:1315-1"}],"prev":{"headline":"Access to restricted PHP code by dynamic static class access in smarty","id":"CVE-2021-21408"},"products":["netty"],"published":"2021-03-30","related":[{"cvss_score":10,"headline":"ProFTPD Improper Access Control","id":"CVE-2015-3306","kev_date_added":"2026-10-08","published":"2015-05-18"},{"cvss_score":9.9,"headline":"RoundCube Webmail Deserialization of Untrusted Data","id":"CVE-2025-49113","kev_date_added":"2026-02-20","published":"2025-06-02"},{"cvss_score":9.8,"headline":"GNU InetUtils Argument Injection","id":"CVE-2026-24061","kev_date_added":"2026-01-26","published":"2026-01-21"},{"cvss_score":9.8,"headline":"Linux Kernel Improper Check for Unusual or Exceptional Conditions","id":"CVE-2025-39682","kev_date_added":"2026-09-18","published":"2025-09-05"},{"cvss_score":9.8,"headline":"Mozilla Firefox Use-After-Free","id":"CVE-2024-9680","kev_date_added":"2024-10-15","published":"2024-10-09"},{"cvss_score":9.8,"headline":"RARLAB UnRAR Directory Traversal","id":"CVE-2022-30333","kev_date_added":"2022-08-09","published":"2022-05-09"},{"cvss_score":9.8,"headline":"Roundcube Webmail SQL Injection","id":"CVE-2021-44026","kev_date_added":"2023-06-22","published":"2021-11-19"}],"sources":[{"class":"attribution","licence":"CVE Terms of Use (MITRE)","name":"CVE List","prefix":"CVE"},{"class":"attribution","licence":"CC BY 4.0","name":"GitHub Advisory Database","prefix":"GHSA"},{"class":"attribution","licence":"CC BY 4.0","name":"SUSE","prefix":"SUSE"},{"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":"yes","exploitation":"none","technical_impact":"partial"},"state":"PUBLISHED","updated":"2026-10-08","vendors":["netty"]},"summary":"Attackers can perform HTTP request smuggling via Netty's HTTP/2 codec when content-length validation is missing, potentially bypassing security controls.","url":"https://insights.sbomify.com/CVE-2021-21409/"}