=========================================================================Ubuntu Security Notice USN-5720-1
November 09, 2022

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

- Ubuntu 16.04 ESM

Summary:

Zstandard could be made to expose sensitive information

Software Description:
- libzstd: fast lossless compression algorithm

Details:

It was discovered that Zstandard was not properly managing file
permissions when generating output files. A local attacker could
possibly use this issue to cause a race condition and gain
unauthorized access to sensitive data.

Update instructions:

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

Ubuntu 16.04 ESM:
   libzstd1 1.3.1+dfsg-1~ubuntu0.16.04.1+esm3
   zstd 1.3.1+dfsg-1~ubuntu0.16.04.1+esm3

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

References:
   https://ubuntu.com/security/notices/USN-5720-1
   CVE-2021-24031, CVE-2021-24032