Several security issues were fixed in Squid.
Jeriko One discovered that Squid incorrectly handled memory when connected to an FTP server. A remote attacker could possibly use this issue to obtain sensitive information from Squid memory. (CVE-2019-12528)
20 February 2020
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in Squid.
Jeriko One discovered that Squid incorrectly handled memory when connected to an FTP server. A remote attacker could possibly use this issue to obtain sensitive information from Squid memory. (CVE-2019-12528)
Regis Leroy discovered that Squid incorrectly handled certain HTTP requests. A remote attacker could possibly use this issue to access server reources prohibited by earlier security filters. (CVE-2020-8449)
Guido Vranken discovered that Squid incorrectly handled certain buffer operations when acting as a reverse proxy. A remote attacker could use this issue to cause Squid to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2020-8450)
Aaron Costello discovered that Squid incorrectly handled certain NTLM authentication credentials. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. (CVE-2020-8517)
The problem can be corrected by updating your system to the following package versions:
To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.
In general, a standard system update will make all the necessary changes.