CVE-2021-21409
Possible request smuggling in HTTP/2 due missing validation of content-length
- State
- Published
- Severity
- 5.9 Medium
- Published
- Mar 30, 2021
- Updated
- Oct 8, 2026
- Reserved
- Dec 22, 2020
Description
Netty is an open-source, asynchronous event-driven network application framework for rapid development of maintainable high performance protocol servers & 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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 3.1 | 5.9 Medium | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N | GitHub_M |
Weaknesses
- CWE-444 Inconsistent Interpretation of HTTP Requests ('HTTP Request Smuggling')
Affected Products
| Product | Versions |
|---|---|
nettynetty |
|
References
- https://github.com/netty/netty/security/advisories/GHSA-f256-j965-7f32
- https://github.com/netty/netty/security/advisories/GHSA-wm47-8v5p-wjpj
- https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-21295
- https://github.com/netty/netty/commit/b0fa4d5aab4215f3c22ce6123dd8dd5f38dc0432
- DSA-4885vendor-advisory
- [zookeeper-dev] 20210407 [jira] [Created] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210407 [jira] [Assigned] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210407 [jira] [Created] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210408 [jira] [Comment Edited] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210408 [jira] [Commented] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-notifications] 20210408 [GitHub] [zookeeper] ayushmantri opened a new pull request #1678: ZOOKEEPER-4278: dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210408 [jira] [Updated] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-notifications] 20210408 [GitHub] [zookeeper] arshadmohammad commented on pull request #1678: ZOOKEEPER-4278: dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-commits] 20210408 [zookeeper] branch master updated: ZOOKEEPER-4278: dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210408 [jira] [Resolved] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-commits] 20210408 [zookeeper] branch branch-3.6 updated: ZOOKEEPER-4278: dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-commits] 20210408 [zookeeper] branch branch-3.7 updated: ZOOKEEPER-4278: dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210408 [jira] [Assigned] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-notifications] 20210408 [GitHub] [zookeeper] asfgit closed pull request #1678: ZOOKEEPER-4278: dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-commits] 20210408 [zookeeper] 01/02: ZOOKEEPER-4278: dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210409 [jira] [Commented] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [pulsar-commits] 20210419 [GitHub] [pulsar] lhotari opened a new pull request #10266: [Security] Upgrade Netty to 4.1.63.Final to address CVE-2021-21409mailing-list
- [pulsar-commits] 20210419 [GitHub] [pulsar] lhotari commented on pull request #10266: [Security] Upgrade Netty to 4.1.63.Final to address CVE-2021-21409mailing-list
- [pulsar-commits] 20210420 [GitHub] [pulsar] eolivelli merged pull request #10266: [Security] Upgrade Netty to 4.1.63.Final to address CVE-2021-21409mailing-list
- [flink-issues] 20210424 [jira] [Created] (FLINK-22441) In Flink v1.11.3 contains netty(version:3.10.6) netty(version:4.1.60) . There are many vulnerabilities, like CVE-2021-21409 etc. please confirm these version and fix. thxmailing-list
- [flink-dev] 20210424 [jira] [Created] (FLINK-22441) In Flink v1.11.3 contains netty(version:3.10.6) netty(version:4.1.60) . There are many vulnerabilities, like CVE-2021-21409 etc. please confirm these version and fix. thxmailing-list
- [flink-issues] 20210426 [jira] [Commented] (FLINK-22441) In Flink v1.11.3 contains netty(version:3.10.6) netty(version:4.1.60) . There are many vulnerabilities, like CVE-2021-21409 etc. please confirm these version and fix. thxmailing-list
- [flink-issues] 20210426 [jira] [Updated] (FLINK-22441) In Flink v1.11.3 contains netty(version:3.10.6) netty(version:4.1.60) . There are many vulnerabilities, like CVE-2021-21409 etc. please confirm these version and fix. thxmailing-list
- [kafka-jira] 20210506 [GitHub] [kafka] dongjinleekr opened a new pull request #10642: KAFKA-12756: Update Zookeeper to 3.6.3 or highermailing-list
- [flink-issues] 20210511 [jira] [Commented] (FLINK-22441) In Flink v1.11.3 contains netty(version:3.10.6) netty(version:4.1.60) . There are many vulnerabilities, like CVE-2021-21409 etc. please confirm these version and fix. thxmailing-list
- [zookeeper-issues] 20210517 [jira] [Updated] (ZOOKEEPER-4295) Upgrade Netty library to > 4.1.60 due to security vulnerability CVE-2021-21409 in branch-3.5mailing-list
- [zookeeper-issues] 20210517 [jira] [Created] (ZOOKEEPER-4295) Upgrade Netty library to > 4.1.60 due to security vulnerability CVE-2021-21409 in branch-3.5mailing-list
- [zookeeper-dev] 20210517 [jira] [Created] (ZOOKEEPER-4295) Upgrade Netty library to > 4.1.60 due to security vulnerability CVE-2021-21409 in branch-3.5mailing-list
- [zookeeper-notifications] 20210517 [GitHub] [zookeeper] gpiyush-dev opened a new pull request #1696: ZOOKEEPER-4295: Upgrade Netty library to > 4.1.60 due to security vulnerability CVE-2021-21409 in branch-3.5mailing-list
- [zookeeper-notifications] 20210521 [GitHub] [zookeeper] maoling commented on pull request #1696: ZOOKEEPER-4295: Upgrade Netty library to > 4.1.60 due to security vulnerability CVE-2021-21409 in branch-3.5mailing-list
- [flink-issues] 20210610 [jira] [Updated] (FLINK-22441) In Flink v1.11.3 contains netty(version:3.10.6) netty(version:4.1.60) . There are many vulnerabilities, like CVE-2021-21409 etc. please confirm these version and fix. thxmailing-list
- [flink-issues] 20210618 [jira] [Updated] (FLINK-22441) In Flink v1.11.3 contains netty(version:3.10.6) netty(version:4.1.60) . There are many vulnerabilities, like CVE-2021-21409 etc. please confirm these version and fix. thxmailing-list
- https://www.oracle.com//security-alerts/cpujul2021.html
- https://security.netapp.com/advisory/ntap-20210604-0003/
- [zookeeper-issues] 20210727 [jira] [Commented] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210727 [jira] [Comment Edited] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-notifications] 20210727 [GitHub] [zookeeper] sandipbhattacharya commented on pull request #1678: ZOOKEEPER-4278: dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [kudu-issues] 20210904 [jira] [Created] (KUDU-3313) There is a CVE-2021-21409 vulnerability in netty version 4.1.60mailing-list
- [kudu-issues] 20210904 [jira] [Updated] (KUDU-3313) There is a CVE-2021-21409 vulnerability in netty version 4.1.60mailing-list
- [kudu-issues] 20210907 [jira] [Resolved] (KUDU-3313) There is a CVE-2021-21409 vulnerability in netty version 4.1.60mailing-list
- [kudu-issues] 20210907 [jira] [Commented] (KUDU-3313) There is a CVE-2021-21409 vulnerability in netty version 4.1.60mailing-list
- [kudu-issues] 20210907 [jira] [Updated] (KUDU-3313) There is a CVE-2021-21409 vulnerability in netty version 4.1.60mailing-list
- [zookeeper-issues] 20210922 [jira] [Commented] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210923 [jira] [Commented] (ZOOKEEPER-4278) dependency-check:check failing - netty-transport-4.1.60.Final CVE-2021-21409mailing-list
- [zookeeper-issues] 20210923 [jira] [Created] (ZOOKEEPER-4385) Backport ZOOKEEPER-4278 to branch-3.5 to Address CVE-2021-21409mailing-list
- [zookeeper-dev] 20210923 [jira] [Created] (ZOOKEEPER-4385) Backport ZOOKEEPER-4278 to branch-3.5 to Address CVE-2021-21409mailing-list
- [zookeeper-issues] 20210923 [jira] [Assigned] (ZOOKEEPER-4385) Backport ZOOKEEPER-4278 to branch-3.5 to Address CVE-2021-21409mailing-list
- [zookeeper-issues] 20210923 [jira] [Updated] (ZOOKEEPER-4385) Backport ZOOKEEPER-4278 to branch-3.5 to Address CVE-2021-21409mailing-list
- [zookeeper-issues] 20210924 [jira] [Resolved] (ZOOKEEPER-4385) Backport ZOOKEEPER-4278 to branch-3.5 to Address CVE-2021-21409mailing-list
- [zookeeper-commits] 20210924 [zookeeper] branch branch-3.5 updated: ZOOKEEPER-4385. Backport ZOOKEEPER-4278 to branch-3.5 to Address CVE-2021-21409mailing-list
- https://www.oracle.com/security-alerts/cpuoct2021.html
- [pulsar-commits] 20211020 [GitHub] [pulsar] Shoothzj opened a new pull request #12437: [Security] Bump grpc to 1.41.0mailing-list
- https://www.oracle.com/security-alerts/cpujan2022.html
- https://www.oracle.com/security-alerts/cpuapr2022.html
Every record here comes from the CVE Program’s CVE List. © 1999–2026 The MITRE Corporation. CVE is a registered trademark of The MITRE Corporation. The records are reproduced under the CVE Program terms of use.