---
id: CVE-2021-43797
title: >-
  Netty is an asynchronous event-driven network application framework for rapid
  development of maintainable high performance protocol servers & clients
summary: >-
  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
  b…
severity: medium
cvss: 6.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N'
cwe:
  - CWE-444
  - CWE-444
vendor: netty
product: netty
affected:
  - netty < 4.1.71
  - quarkus < 2.5.3
  - oncommand_workflow_automation
  - snapcenter
  - banking_deposits_and_lines_of_credit_servicing = 2.7
  - banking_party_management = 2.7.0
  - banking_platform = 2.6.2
  - coherence = 12.2.1.4.0
  - coherence = 14.1.1.0.0
  - communications_cloud_native_core_binding_support_function = 1.11.0
  - communications_cloud_native_core_network_slice_selection_function = 1.8.0
  - communications_cloud_native_core_policy = 1.15.0
  - communications_cloud_native_core_security_edge_protection_proxy = 1.7.0
  - communications_cloud_native_core_unified_data_repository = 1.15.0
  - communications_design_studio = 7.4.2
  - communications_instant_messaging_server = 8.1
  - helidon = 1.4.10
  - helidon = 2.4.0
  - peoplesoft_enterprise_peopletools = 8.58
  - peoplesoft_enterprise_peopletools = 8.59
  - debian_linux = 10.0
  - debian_linux = 11.0
patched:
  - netty 4.1.71
  - quarkus 2.5.3
published: '2021-12-09'
updated: '2026-10-08'
sourceUpdated: '2026-10-08T22:17:12.930'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2021-43797'
references:
  - url: >-
      https://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323
    label: security-advisories@github.com
  - url: 'https://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqq'
    label: security-advisories@github.com
  - url: 'https://lists.debian.org/debian-lts-announce/2023/01/msg00008.html'
    label: security-advisories@github.com
  - url: 'https://security.netapp.com/advisory/ntap-20220107-0003/'
    label: security-advisories@github.com
  - url: 'https://www.debian.org/security/2023/dsa-5316'
    label: security-advisories@github.com
  - url: 'https://www.oracle.com/security-alerts/cpuapr2022.html'
    label: security-advisories@github.com
  - url: 'https://www.oracle.com/security-alerts/cpujul2022.html'
    label: security-advisories@github.com
  - url: >-
      https://github.com/netty/netty/commit/07aa6b5938a8b6ed7a6586e066400e2643897323
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://github.com/netty/netty/security/advisories/GHSA-wx5j-54mm-rqqq'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://lists.debian.org/debian-lts-announce/2023/01/msg00008.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://security.netapp.com/advisory/ntap-20220107-0003/'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.debian.org/security/2023/dsa-5316'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpuapr2022.html'
    label: af854a3a-2127-422b-91ae-364da2661108
  - url: 'https://www.oracle.com/security-alerts/cpujul2022.html'
    label: af854a3a-2127-422b-91ae-364da2661108
tags:
  - nvd
epss: 0.02884
epssPercentile: 0.86454
ingestedAt: '2026-10-08T23:16:47.326Z'
---

## Overview

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.

## Affected

- `netty < 4.1.71`
- `quarkus < 2.5.3`
- `oncommand_workflow_automation`
- `snapcenter`
- `banking_deposits_and_lines_of_credit_servicing = 2.7`
- `banking_party_management = 2.7.0`
- `banking_platform = 2.6.2`
- `coherence = 12.2.1.4.0`
- `coherence = 14.1.1.0.0`
- `communications_cloud_native_core_binding_support_function = 1.11.0`
- `communications_cloud_native_core_network_slice_selection_function = 1.8.0`
- `communications_cloud_native_core_policy = 1.15.0`
- `communications_cloud_native_core_security_edge_protection_proxy = 1.7.0`
- `communications_cloud_native_core_unified_data_repository = 1.15.0`
- `communications_design_studio = 7.4.2`
- `communications_instant_messaging_server = 8.1`
- `helidon = 1.4.10`
- `helidon = 2.4.0`
- `peoplesoft_enterprise_peopletools = 8.58`
- `peoplesoft_enterprise_peopletools = 8.59`
- `debian_linux = 10.0`
- `debian_linux = 11.0`

## Remediation

Upgrade past the affected range:

- `netty 4.1.71`
- `quarkus 2.5.3`