SB2020051520 - Red Hat Enterprise Linux 8 update for kernel-rt 



SB2020051520 - Red Hat Enterprise Linux 8 update for kernel-rt

Published: May 15, 2020 Updated: May 22, 2020

Security Bulletin ID SB2020051520
Severity
Medium
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Medium 50% Low 50%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 secuirty vulnerabilities.


1) Information disclosure (CVE-ID: CVE-2020-2732)

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists due to incomplete implementation of vmx_check_intercept on Intel processors in KVM in Linux kernel, which leads to  I/O or MSR interception bitmaps are not checked. A remote attacker with access to guest operating system (e.g. L2 guest) can trick the L0 hypervisor into accessing sensitive information on the L1 hypervisor.


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.


Remediation

Install update from vendor's website.