SB2021100630 - Ubuntu update for linux-oem-5.10
Published: October 6, 2021
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 5 secuirty vulnerabilities.
1) Improper Privilege Management (CVE-ID: CVE-2021-41073)
The vulnerability allows a local user to escalate privileges.
The vulnerability exists due to improper privilege management within the loop_rw_iter() function in fs/io_uring.c in Linux kernel. A local user can escalate privileges on the system by using IORING_OP_PROVIDE_BUFFERS to trigger a free of a kernel buffer.
2) Protection Mechanism Failure (CVE-ID: CVE-2020-26541)
The vulnerability allows a local user to escalate privileges on the system.
The Linux kernel through 5.8.13 does not properly enforce the Secure
Boot Forbidden Signature Database (aka dbx) protection mechanism. This
affects certs/blacklist.c and certs/system_keyring.c. A local user can escalate privileges on the system.
3) 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.
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.
5) Race condition (CVE-ID: CVE-2021-38199)
The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.
The vulnerability exists due to fs/nfs/nfs4client.c in the Linux kernel has incorrect connection-setup ordering. A remote attacker with access to a remote NFSv4 server can perform a denial of service (DoS) attack by arranging the server to be unreachable during trunking detection.
Remediation
Install update from vendor's website.