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

USN-4447-1: libssh vulnerability

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Ubuntu Security Notice USN-4447-1
August 04, 2020

libssh 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

Summary:

libssh could be made to crash if it received a specially crafted request.

Software Description:
- libssh: None

Details:

It was discovered that libssh incorrectly handled certain requests.
An attacker could possibly use this issue to cause a denial of service.

Update instructions:

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

Ubuntu 20.04 LTS:
libssh-4 0.9.3-2ubuntu2.1

Ubuntu 18.04 LTS:
libssh-4 0.8.0~20170825.94fa1e38-1ubuntu0.7

Ubuntu 16.04 LTS:
libssh-4 0.6.3-4.3ubuntu0.6

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

References:
  https://usn.ubuntu.com/4447-1
CVE-2020-16135

Package Information:
  https://launchpad.net/ubuntu/+source/libssh/0.9.3-2ubuntu2.1
  https://launchpad.net/ubuntu/+source/libssh/0.8.0~20170825.94fa1e38-1ubuntu0.7
  https://launchpad.net/ubuntu/+source/libssh/0.6.3-4.3ubuntu0.6