{"cve":"CVE-2021-43797","nvd":{"published":"2021-12-09T19:15:07.960","modified":"2026-10-08T22:17:12.930","status":"Modified","description":"Netty is an asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & clients. Netty prior to version 4.1.71.Final skips control chars when they are present at the beginning / end of the header name. It should instead fail fast as these are not allowed by the spec and could lead to HTTP request smuggling. Failing to do the validation might cause netty to \"sanitize\" header names before it forward these to another remote system when used as proxy. This remote system can't see the invalid usage anymore, and therefore does not do the validation itself. Users should upgrade to version 4.1.71.Final.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N","score":6.5},"cwes":["CWE-444"],"references":["https://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323","https://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqq","https://lists.debian.org/debian-lts-announce/2023/01/msg00008.html","https://security.netapp.com/advisory/ntap-20220107-0003/","https://www.debian.org/security/2023/dsa-5316"],"products":["debian:debian_linux","netapp:oncommand_workflow_automation","netapp:snapcenter","netty:netty","oracle:banking_deposits_and_lines_of_credit_servicing","oracle:banking_party_management","oracle:banking_platform","oracle:coherence","oracle:communications_cloud_native_core_binding_support_function","oracle:communications_cloud_native_core_network_slice_selection_function","oracle:communications_cloud_native_core_policy","oracle:communications_cloud_native_core_security_edge_protection_proxy","oracle:communications_cloud_native_core_unified_data_repository","oracle:communications_design_studio","oracle:communications_instant_messaging_server","oracle:helidon","oracle:peoplesoft_enterprise_peopletools","quarkus:quarkus"],"source":"nvd","synced_at":"2026-10-19T21:25:41.256909649+00:00"},"epss":{"cve":"CVE-2021-43797","score":0.02884,"percentile":0.86766,"date":"2026-10-25"},"kev":null,"osv":[{"id":"GHSA-wx5j-54mm-rqqq","url":"https://osv.dev/vulnerability/GHSA-wx5j-54mm-rqqq","summary":"HTTP request smuggling in netty","modified":"2026-09-10T03:49:01.090670310Z","packages":[{"ecosystem":"Maven","name":"io.netty:netty-codec-http","purl":"pkg:maven/io.netty/netty-codec-http","ranges":[">=4.0.0 <4.1.71.Final"],"fixed":["4.1.71.Final"]},{"ecosystem":"Maven","name":"org.jboss.netty:netty","purl":"pkg:maven/org.jboss.netty/netty","ranges":["all versions"],"fixed":[]},{"ecosystem":"Maven","name":"io.netty:netty","purl":"pkg:maven/io.netty/netty","ranges":["all versions"],"fixed":[]}]}],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}