SB2021090724 - Red Hat Enterprise Linux 8.1 Extended Update Support update for kernel
Published: September 7, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 3 secuirty vulnerabilities.
1) 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.
2) Use-after-free (CVE-ID: CVE-2021-3715)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a use-after-free error in the "Routing decision" classifier in the Linux kernel's Traffic Control networking subsystem (route4_change() function in net/sched/cls_route.c) in the way it handled changing of classification filters. A local user can trigger a use-after-free error and execute arbitrary code with elevated privileges.
3) Out-of-bounds write (CVE-ID: CVE-2021-37576)
The vulnerability allows a remote user to escalate privileges on the system.
The vulnerability exists due to a boundary error in arch/powerpc/kvm/book3s_rtas.c in the Linux kernel through 5.13.5 on the powerpc platform. An attacker on KVM guest OS can cause host OS memory corruption via rtas_args.nargs and execute arbitrary code on the host OS.
Remediation
Install update from vendor's website.