SB2021080536 - SUSE update for the Linux Kernel

Description

This security bulletin contains information about 4 secuirty vulnerabilities.

1) Out-of-bounds write (CVE-ID: CVE-2021-22555)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error when processing untrusted input in net/netfilter/x_tables.c in Linux kernel. A local user can run a specially crafted program to trigger an out-of-bounds write and execute arbitrary code with elevated privileges.

2) Improper Verification of Cryptographic Signature (CVE-ID: CVE-2021-35039)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to improper signature handling in the kernel/module.c in Linux kernel. If the kernel module is not signed, it still can be loaded into the system via init_module if module.sig_enforce=1 command-line argument is used. As a result, a local user can load unsigned and potentially malicious kernel modules.

3) Race condition (CVE-ID: CVE-2021-3609)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a race condition in the CAN BCM networking protocol (net/can/bcm.c) in the Linux kernel ranging from version 2.6.25 to mainline 5.13-rc6. A local user can exploit the race and gain unauthorized access to sensitive information and escalate privileges on the system.

4) Out-of-bounds write (CVE-ID: CVE-2021-3612)

The vulnerability allows a local user to escalate privileges on the system.

The vulnerability exists due to a boundary error in joystick devices subsystem in Linux kernel. A local user can make a specially crafted JSIOCSBTNMAP IOCTL call, trigger out-of-bounds write and execute arbitrary code with escalated privileges.

Remediation

Install update from vendor's website.

References

• https://www.suse.com/support/update/announcement/2021/suse-su-20212599-2/