A libssh2t security update has been released for Ubuntu Linux 14.04 LTS, 16.04 LTS, 18.04 LTS, and 20.04 LTS.

[USN-6371-1] libssh2 vulnerability

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Ubuntu Security Notice USN-6371-1
September 14, 2023

libssh2 vulnerability
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A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS
- Ubuntu 16.04 LTS (Available with Ubuntu Pro)
- Ubuntu 14.04 LTS (Available with Ubuntu Pro)

Summary:

libssh2 could be made to crash if it received specially
crafted network traffic.

Software Description:
- libssh2: Client-side C library implementing the SSH2 protocol

Details:

It was discovered that libssh2 incorrectly handled memory
access. An attacker could possibly use this issue to cause
a crash.

Update instructions:

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

Ubuntu 20.04 LTS:
  libssh2-1                       1.8.0-2.1ubuntu0.1

Ubuntu 18.04 LTS:
  libssh2-1                       1.8.0-1ubuntu0.1

Ubuntu 16.04 LTS (Available with Ubuntu Pro):
  libssh2-1                       1.5.0-2ubuntu0.1+esm2

Ubuntu 14.04 LTS (Available with Ubuntu Pro):
  libssh2-1                       1.4.3-2ubuntu0.2+esm3

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

References:
  https://ubuntu.com/security/notices/USN-6371-1
  CVE-2020-22218

Package Information:
  https://launchpad.net/ubuntu/+source/libssh2/1.8.0-2.1ubuntu0.1
  https://launchpad.net/ubuntu/+source/libssh2/1.8.0-1ubuntu0.1