=========================================================================Ubuntu Security Notice USN-4760-1
March 08, 2021

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

- Ubuntu 20.10
- Ubuntu 20.04 LTS
- Ubuntu 18.04 LTS

Summary:

libzstd could be made to expose sensitive information.

Software Description:
- libzstd: fast lossless compression algorithm

Details:

It was discovered that libzstd incorrectly handled file permissions. A
local attacker could possibly use this issue to access certain files,
contrary to expectations.

Update instructions:

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

Ubuntu 20.10:
  libzstd1                        1.4.5+dfsg-4ubuntu0.1
  zstd                            1.4.5+dfsg-4ubuntu0.1

Ubuntu 20.04 LTS:
  libzstd1                        1.4.4+dfsg-3ubuntu0.1
  zstd                            1.4.4+dfsg-3ubuntu0.1

Ubuntu 18.04 LTS:
  libzstd1                        1.3.3+dfsg-2ubuntu1.2
  zstd                            1.3.3+dfsg-2ubuntu1.2

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

References:
  https://ubuntu.com/security/notices/USN-4760-1
  CVE-2021-24031, CVE-2021-24032

Package Information:
  https://launchpad.net/ubuntu/+source/libzstd/1.4.5+dfsg-4ubuntu0.1
  https://launchpad.net/ubuntu/+source/libzstd/1.4.4+dfsg-3ubuntu0.1
  https://launchpad.net/ubuntu/+source/libzstd/1.3.3+dfsg-2ubuntu1.2