Resource Exhaustion Affecting netty package, versions <1:4.1.45-1ubuntu0.1~esm1


Severity

Recommended
medium

Based on Ubuntu security rating.

Threat Intelligence

EPSS
9.44% (95th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-UBUNTU2004-NETTY-1147619
  • published21 Mar 2026
  • disclosed7 Apr 2020

Introduced: 7 Apr 2020

CVE-2020-11612  (opens in a new tab)
CWE-400  (opens in a new tab)

How to fix?

Upgrade Ubuntu:20.04 netty to version 1:4.1.45-1ubuntu0.1~esm1 or higher.

NVD Description

Note: Versions mentioned in the description apply only to the upstream netty package and not the netty package as distributed by Ubuntu. See How to fix? for Ubuntu:20.04 relevant fixed versions and status.

The ZlibDecoders in Netty 4.1.x before 4.1.46 allow for unbounded memory allocation while decoding a ZlibEncoded byte stream. An attacker could send a large ZlibEncoded byte stream to the Netty server, forcing the server to allocate all of its free memory to a single decoder.

References

CVSS Base Scores

version 3.1