Ubuntu 6441-2: Linux kernel (GCP) vulnerabilities

October 23, 2023

Several security issues were fixed in the Linux kernel.

Summary

A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 18.04 LTS (Available with Ubuntu Pro) Summary: Several security issues were fixed in the Linux kernel. Software Description: - linux-gcp-5.4: Linux kernel for Google Cloud Platform (GCP) systems Details: Ross Lagerwall discovered that the Xen netback backend driver in the Linux kernel did not properly handle certain unusual packets from a paravirtualized network frontend, leading to a buffer overflow. An attacker in a guest VM could use this to cause a denial of service (host system crash) or possibly execute arbitrary code. (CVE-2023-34319) Kyle Zeng discovered that the networking stack implementation in the Linux kernel did not properly validate skb object size in certain conditions. An attacker could use this cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2023-42752) Kyle Zeng discovered that the netfiler subsystem in the Linux kernel did not properly calculate array offsets, leading to a out-of-bounds write vulnerability. A local user could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2023-42753) Kyle Zeng discovered that the IPv4 Resource Reservation Protocol (RSVP) classifier implementation in the Linux kernel contained an out-of-bounds read vulnerability. A local attacker could use this to cause a denial of service (system crash). Please note that kernel packet classifier support for RSVP has been removed to resolve this vulnerability. (CVE-2023-42755) Kyle Zeng discovered that the netfilter subsystem in the Linux kernel contained a race condition in IP set operations in certain situations. A local attacker could use this to cause a denial of service (system crash). (CVE-2023-42756) Bing-Jhong Billy Jheng discovered that the Unix domain socket implementation in the Linux kernel contained a race condition in certain situations, leading to a use-after-free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2023-4622) Budimir Markovic discovered that the qdisc implementation in the Linux kernel did not properly validate inner classes, leading to a use-after-free vulnerability. A local user could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2023-4623) Alex Birnberg discovered that the netfilter subsystem in the Linux kernel did not properly validate register length, leading to an out-of- bounds write vulnerability. A local attacker could possibly use this to cause a denial of service (system crash). (CVE-2023-4881) It was discovered that the Quick Fair Queueing scheduler implementation in the Linux kernel did not properly handle network packets in certain conditions, leading to a use after free vulnerability. A local attacker could use this to cause a denial of service (system crash) or possibly execute arbitrary code. (CVE-2023-4921)

Update Instructions

The problem can be corrected by updating your system to the following package versions: Ubuntu 18.04 LTS (Available with Ubuntu Pro): linux-image-5.4.0-1116-gcp 5.4.0-1116.125~18.04.1 linux-image-gcp 5.4.0.1116.92 After a standard system update you need to reboot your computer to make all the necessary changes. ATTENTION: Due to an unavoidable ABI change the kernel updates have been given a new version number, which requires you to recompile and reinstall all third party kernel modules you might have installed. Unless you manually uninstalled the standard kernel metapackages (e.g. linux-generic, linux-generic-lts-RELEASE, linux-virtual, linux-powerpc), a standard system upgrade will automatically perform this as well.