Two Extreme Linux Vulnerabilities Influence 40% of Ubuntu Customers

Jul 27, 2023THNLinux / Endpoint Safety

Cybersecurity researchers have disclosed two high-severity safety flaws within the Ubuntu kernel that would pave the best way for native privilege escalation assaults.

Cloud safety agency Wiz, in a report shared with The Hacker Information, mentioned the easy-to-exploit shortcomings have the potential to impression 40% of Ubuntu customers.

“The impacted Ubuntu variations are prevalent within the cloud as they function the default working methods for a number of [cloud service providers],” safety researchers Sagi Tzadik and Shir Tamari mentioned.

The vulnerabilities – tracked as CVE-2023-32629 and 2023-2640 (CVSS scores: 7.8) and dubbed GameOver(lay) – are current in a module referred to as OverlayFS and come up on account of insufficient permissions checks in sure eventualities, enabling a neighborhood attacker to realize elevated privileges.

Overlay Filesystem refers to a union mount file system that makes it potential to mix a number of listing timber or file methods right into a single, unified filesystem.

A quick description of the 2 flaws is under –

• CVE-2023-2640 – On Ubuntu kernels carrying each c914c0e27eb0 and “UBUNTU: SAUCE: overlayfs: Skip permission checking for trusted.overlayfs.* xattrs,” an unprivileged person could set privileged prolonged attributes on the mounted information, main them to be set on the higher information with out the suitable safety checks.
• CVE-2023-32629 – Native privilege escalation vulnerability in Ubuntu Kernels overlayfs ovl_copy_up_meta_inode_data skip permission checks when calling ovl_do_setxattr on Ubuntu kernels

In a nutshell, GameOver(lay) makes it potential to “craft an executable file with scoped file capabilities and trick the Ubuntu Kernel into copying it to a distinct

location with unscoped capabilities, granting anybody who executes it root-like privileges.”

Following accountable disclosure, the vulnerabilities have been mounted by Ubuntu as of July 24, 2023.

The findings underscore the truth that delicate adjustments within the Linux kernel launched by Ubuntu may have unexpected implications, Wiz CTO and co-founder Ami Luttwak mentioned in an announcement shared with the publication.

“Each vulnerabilities are distinctive to Ubuntu kernels since they stemmed from Ubuntu’s particular person adjustments to the OverlayFS module,” the researchers mentioned, including the problems are corresponding to different vulnerabilities similar to CVE-2016-1576, CVE-2021-3493, CVE-2021-3847, and CVE-2023-0386.