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Vulnerability · Published Mar 30, 2021 · Assigned by GitHub_M

CVE-2021-21409Possible request smuggling in HTTP/2 due missing validation of content-length

Medium 5.9

In plain English

A medium-severity security flaw in netty from netty. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 4.9% (higher than 92% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.9Medium
Exploit odds (30 days)4.9%top 7.8% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12netty1:4.1.48-4DEBIAN-CVE-2021-21409
Debian:13netty1:4.1.48-4DEBIAN-CVE-2021-21409
Debian:14netty1:4.1.48-4DEBIAN-CVE-2021-21409
Mavenio.netty:nettyno fix listedGHSA-f256-j965-7f32
Mavenio.netty:netty-codec-http24.1.61.FinalGHSA-f256-j965-7f32
Mavenorg.jboss.netty:nettyno fix listedGHSA-f256-j965-7f32
Rocky Linux:8libdb0:5.3.28-42.el8_4RLSA-2022:5498
Ubuntu:22.04:LTSnetty1:4.1.48-4+deb11u1build0.22.04.1USN-6049-1
Ubuntu:22.04:LTSnetty1:4.1.48-4+deb11u1build0.22.04.1UBUNTU-CVE-2021-21409

Affected products (as reported)

VendorProductVersions
netty netty < 4.1.61.Final

Weakness: CWE-444 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N

References