Low

Memory exhaustion in http4s-async-http-client with large or malicious compressed responses

  • Disclosed: 16.10.2020
  • Updated: 11.10.2026 12:21

Impact

A server we connect to with http4s-async-http-client could theoretically respond with a large or malicious compressed stream and exhaust memory in the client JVM. It does not affect http4s servers, other client backends, or clients that speak only to trusted servers. This is related to a transitive dependency on netty-codec-4.1.45.Final, which is affected by CVE-2020-11612.

Patches

Upgrade to http4s-async-http-client >= 0.21.8. All 1.0 milestones are also safe.

Workarounds

Add an explicit runtime dependency on async-http-client's netty dependencies that evicts them to an unaffected version:

scala
libraryDependencies ++= Seq(
  "io.netty" %  "netty-codec"         % "4.1.53.Final" % Runtime,
  "io.netty" %  "netty-codec-socks"   % "4.1.53.Final" % Runtime,
  "io.netty" %  "netty-handler-proxy" % "4.1.53.Final" % Runtime,
  "io.netty" %  "netty-common"        % "4.1.53.Final" % Runtime,
  "io.netty" %  "netty-transport"     % "4.1.53.Final" % Runtime,
  "io.netty" %  "netty-handler"       % "4.1.53.Final" % Runtime,
  "io.netty" %  "netty-resolver-dns"  % "4.1.53.Final" % Runtime
)

References

For more information

If you have any questions or comments about this advisory:

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Java / Kotlin (Maven) org.http4s:http4s-async-http-client_2.12 < 0.21.8 0.21.8
Java / Kotlin (Maven) org.http4s:http4s-async-http-client_2.13 < 0.21.8 0.21.8

References

CVSS score -
Weakness (CWE)
CWE-400
Platform
Java / Kotlin (Maven)
Package
org.http4s:http4s-async-http-client_2.12, org.http4s:http4s-async-http-client_2.13
Disclosed
16.10.2020
Updated
11.10.2026 12:21

Sources and licenses

OSV / GitHub Advisory Database - GHSA-8hxh-r6f7-jf45 - CC BY 4.0

Vulnerability history: org.http4s:http4s-async-http-client_2.13

All published vulnerabilities of this package (Java / Kotlin (Maven)), newest first. Shows whether this is a one-off slip or a package that needs watching.

This is the only known vulnerability of this package.

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