SB2020061019 - Red Hat Enterprise Linux 8 update for kernel



SB2020061019 - Red Hat Enterprise Linux 8 update for kernel

Published: June 10, 2020

Security Bulletin ID SB2020061019
Severity
Medium
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 20% Low 80%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 secuirty vulnerabilities.


1) Information disclosure (CVE-ID: CVE-2019-18660)

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

The vulnerability exists due to absent protection in Linux kernel on powerpc against the Spectre-RSB, related to arch/powerpc/kernel/entry_64.S and arch/powerpc/kernel/security.c. A local user can gain unauthorized access to sensitive information on the system.


2) NULL pointer dereference (CVE-ID: CVE-2020-10711)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to a NULL pointer dereference error in the Linux kernel's SELinux subsystem when importing the Commercial IP Security Option (CIPSO) protocol's category bitmap into the SELinux extensible bitmap via the' ebitmap_netlbl_import' routine. While processing the CIPSO restricted bitmap tag in the 'cipso_v4_parsetag_rbm' routine, it sets the security attribute to indicate that the category bitmap is present, even if it has not been allocated.

A remote attacker can send specially crafted packets the affected system, trigger a NULL pointer dereference error and crash the Linux kernel.


3) Race condition (CVE-ID: CVE-2020-11884)

The vulnerability allows a local authenticated user to execute arbitrary code.

In the Linux kernel through 5.6.7 on the s390 platform, code execution may occur because of a race condition, as demonstrated by code in enable_sacf_uaccess in arch/s390/lib/uaccess.c that fails to protect against a concurrent page table upgrade, aka CID-3f777e19d171. A crash could also occur.


4) Use-after-free (CVE-ID: CVE-2020-12657)

The vulnerability allows a local user to compromise vulnerable system.

The vulnerability exists due to a use-after-free error in "block/bfq-iosched.c" file related to "bfq_idle_slice_timer_body". A local user can execute arbitrary code on the target system.

Successful exploitation of the vulnerability may allow an attacker to compromise vulnerable system.


5) Information disclosure (CVE-ID: CVE-2020-0543)

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

The vulnerability exists due to incomplete cleanup from specific special register read operations in some Intel(R) Processors. A local user can gain unauthorized access to sensitive information on the system.


Remediation

Install update from vendor's website.