Several security issues were fixed in Squid.
Jeriko One and Kristoffer Danielsson discovered that Squid incorrectly handled certain URN requests. A remote attacker could possibly use this issue to bypass access checks and access restricted servers. This issue was only addressed in Ubuntu 19.04 and Ubuntu 19.10. (CVE-2019-12523)
4 December 2019
A security issue affects these releases of Ubuntu and its derivatives:
Several security issues were fixed in Squid.
Jeriko One and Kristoffer Danielsson discovered that Squid incorrectly handled certain URN requests. A remote attacker could possibly use this issue to bypass access checks and access restricted servers. This issue was only addressed in Ubuntu 19.04 and Ubuntu 19.10. (CVE-2019-12523)
Jeriko One discovered that Squid incorrectly handed URN responses. A remote attacker could use this issue to cause Squid to crash, resulting in a denial of service, or possibly execute arbitrary code. (CVE-2019-12526)
Alex Rousskov discovered that Squid incorrectly handled certain strings. A remote attacker could possibly use this issue to cause Squid to crash, resulting in a denial of service. This issue only affected Ubuntu 19.04. (CVE-2019-12854)
Jeriko One and Kristoffer Danielsson discovered that Squid incorrectly handled certain input. A remote attacker could use this issue to cause Squid to crash, resulting in a denial of service, or possibly execute arbitrary code. This issue was only addressed in Ubuntu 19.04 and Ubuntu 19.10. (CVE-2019-18676)
Kristoffer Danielsson discovered that Squid incorrectly handled certain messages. This issue could result in traffic being redirected to origins it should not be delivered to. (CVE-2019-18677)
Régis Leroy discovered that Squid incorrectly handled certain HTTP request headers. A remote attacker could use this to smuggle HTTP requests and corrupt caches with arbitrary content. (CVE-2019-18678)
David Fifield discovered that Squid incorrectly handled HTTP Digest Authentication. A remote attacker could possibly use this issue to obtain pointer contents and bypass ASLR protections. (CVE-2019-18679)
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.
Vulmon