SB2020042441 - Amazon Linux AMI update for kernel 



SB2020042441 - Amazon Linux AMI update for kernel

Published: April 24, 2020

Security Bulletin ID SB2020042441
Severity
Low
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 secuirty vulnerabilities.


1) Stack-based buffer overflow (CVE-ID: CVE-2020-10942)

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

The vulnerability exists due to a boundary error within the get_raw_socket() function in drivers/vhost/net.c due to lack of validation of the sk_family field. A local user can perform a specially crafted system call, trigger stack overflow and crash the kernel.



2) 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.


3) Use-after-free (CVE-ID: CVE-2020-8648)

The vulnerability allows a local authenticated user to #BASIC_IMPACT#.

There is a use-after-free vulnerability in the Linux kernel through 5.5.2 in the n_tty_receive_buf_common function in drivers/tty/n_tty.c.


Remediation

Install update from vendor's website.