SB2021072273 - Red Hat Enterprise Linux 7 update for kernel-rt



SB2021072273 - Red Hat Enterprise Linux 7 update for kernel-rt

Published: July 22, 2021 Updated: August 9, 2022

Security Bulletin ID SB2021072273
Severity
Medium
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 secuirty vulnerabilities.


1) Use-after-free (CVE-ID: CVE-2019-20934)

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

The vulnerability exists due to a use-after-free error in Linux fair scheduler within the show_numa_stats() function, caused by improperly freed NUMA fault statistics. A local user can trigger a use-after-free error and escalate privileges on the system.



2) NULL pointer dereference (CVE-ID: CVE-2020-11668)

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

The vulnerability exists due to a NULL pointer dereference error within the drivers/media/usb/gspca/xirlink_cit.c in Xirlink camera USB driver. A local user can pass specially crafted data to the driver and perform a denial of service (DoS) attack.


3) Use-after-free (CVE-ID: CVE-2021-33033)

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

The vulnerability exists due to improper handling of the CIPSO and CALIPSO refcounting for the DOI definitions in cipso_v4_genopt(0 function in net/ipv4/cipso_ipv4.c in Linux kernel. A local user can trigger a use-after-free error and execute arbitrary code with escalated privileges.


4) Use-after-free (CVE-ID: CVE-2021-33034)

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

The vulnerability exists due to a use-after-free error in net/bluetooth/hci_event.c when destroying an hci_chan. A local user can escalate privileges on the system.



5) Integer overflow (CVE-ID: CVE-2021-33909)

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

The vulnerability exists due to integer overflow during size_t-to-int conversion when creating, mounting, and deleting a deep directory structure whose total path length exceeds 1GB. An unprivileged local user can write up to 10-byte string to an offset of exactly -2GB-10B below the beginning of a vmalloc()ated kernel buffer.

Successful exploitation of vulnerability may allow an attacker to exploit the our-of-bounds write vulnerability to execute arbitrary code with root privileges.


Remediation

Install update from vendor's website.