An iperf3 security update has been released for Ubuntu Linux 16.04 LTS, 18.04 LTS, and 20.04 LTS.

[USN-6431-1] iperf3 vulnerabilities

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Ubuntu Security Notice USN-6431-1
October 16, 2023

iperf3 vulnerabilities
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS (Available with Ubuntu Pro)
- Ubuntu 18.04 LTS (Available with Ubuntu Pro)
- Ubuntu 16.04 LTS (Available with Ubuntu Pro)

Summary:

Several security issues were fixed in iperf3.

Software Description:
- iperf3: Internet Protocol bandwidth measuring tool

Details:

It was discovered that iperf3 did not properly manage certain inputs,
which could lead to a crash. A remote attacker could possibly use this
issue to cause a denial of service. (CVE-2023-38403)

Jorge Sancho Larraz discovered that iperf3 did not properly manage certain
inputs, which could cause the server process to stop responding, waiting
for input on the control connection. A remote attacker could possibly use
this issue to cause a denial of service. (LP: #2038654)

Update instructions:

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 20.04 LTS (Available with Ubuntu Pro):
  iperf3                          3.7-3ubuntu0.1~esm1
  libiperf0                       3.7-3ubuntu0.1~esm1

Ubuntu 18.04 LTS (Available with Ubuntu Pro):
  iperf3                          3.1.3-1ubuntu0.1~esm1
  libiperf0                       3.1.3-1ubuntu0.1~esm1

Ubuntu 16.04 LTS (Available with Ubuntu Pro):
  iperf3                          3.0.11-1ubuntu0.1~esm2
  libiperf0                       3.0.11-1ubuntu0.1~esm2

In general, a standard system update will make all the necessary changes.

References:
  https://ubuntu.com/security/notices/USN-6431-1
  CVE-2023-38403, https://launchpad.net/bugs/2038654