SB2021081064 - SUSE update for the Linux Kernel
Published: August 10, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 7 secuirty vulnerabilities.
1) Information disclosure (CVE-ID: CVE-2021-21781)
The vulnerability allows a local user to gain access to potentially sensitive information.
The vulnerability exists due to excessive data output in the ARM SIGPAGE functionality. A userland application can read the contents of the sigpage, which can leak kernel memory contents.
2) Buffer overflow (CVE-ID: CVE-2021-22543)
The vulnerability allows a local user to escalate privileges on the system.
The vulnerability exists due to a boundary error in Linux kernel when handling VM_IO|VM_PFNMAP vmas in KVM. A local user can can bypass RO checks and cause the pages to get freed while still accessible by the VMM and guest. As a result, an attacker with the ability to start and control a VM to read/write random pages of memory, can trigger memory corruption and execute arbitrary code with elevated privileges.
3) 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.
4) 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.
5) 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.
6) NULL pointer dereference (CVE-ID: CVE-2021-3659)
The vulnerability allows a local usre to perform a denial of service (DoS) attack.
The vulnerability exists due to a NULL pointer dereference error in the way the user closes the LR-WPAN connection within the IEEE 802.15.4 wireless networking subsystem. A local user can perform a denial of service (DoS) attack.
7) 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.