SB2023062157 - Ubuntu Linux kernel live patch

Description

This security bulletin contains information about 6 secuirty vulnerabilities.

1) Permissions, Privileges, and Access Controls (CVE-ID: CVE-2023-0386)

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

The vulnerability exists due to unauthorized access to execution of setuid files in OverlayFS subsystem when copying a capable file from a nosuid mount into another mount. A local user can execute arbitrary code with root privileges.

2) Out-of-bounds read (CVE-ID: CVE-2023-1380)

The vulnerability allows a local user to gain access to potentially sensitive information.

The vulnerability exists due to a boundary condition within the Broadcom Full MAC Wi-Fi driver (brcmfmac.ko). A local user can trigger an out-of-bounds read error and read contents of kernel memory on the system.

3) Use-after-free (CVE-ID: CVE-2023-1872)

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

The vulnerability exists due to a use-after-free error within the io_file_get_fixed function. A local user can trigger a use-after-free error and execute arbitrary code with elevated privileges.

4) Race condition (CVE-ID: CVE-2023-2612)

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to a race condition within the shiftfs filesystem when handling inode locking in some
situations. A local user can exploit the race and cause a denial of service (kernel deadlock).

5) Out-of-bounds write (CVE-ID: CVE-2023-31436)

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

The vulnerability exists due to a boundary error within the qfq_change_class() function in net/sched/sch_qfq.c when handling the MTU value provided to the QFQ Scheduler. A local user can trigger an out-of-bounds write and execute arbitrary code with elevated privileges.

6) Use-after-free (CVE-ID: CVE-2023-32233)

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

The vulnerability exists due to a use-after-free error in Netfilter nf_tables when processing batch requests. A local user can trigger a use-after-free error and execute arbitrary code with root privileges.

Remediation

Install update from vendor's website.

References

• https://ubuntu.com/security/notices/LSN-0095-1