SB2018060816 - Amazon Linux AMI update for kernel



SB2018060816 - Amazon Linux AMI update for kernel

Published: June 8, 2018 Updated: June 12, 2018

Security Bulletin ID SB2018060816
Severity
High
Patch available
YES
Number of vulnerabilities 2
Exploitation vector Local access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 2 secuirty vulnerabilities.


1) Improper input validation (CVE-ID: CVE-2018-1120)

The vulnerability allows a local user to cause DoS condition on the target system.

The weakness exists due to insufficient validation of user-supplied input. A local user can block any read() access to /proc/PID/cmdline by mmap()ing a FUSE file (Filesystem in Userspace) onto this process's command-line arguments, block pgrep, pidof, pkill, ps, and w, either forever (a denial of service), or for some controlled time (a synchronization tool for exploiting other vulnerabilities).

2) Speculative Store Bypass (CVE-ID: CVE-2018-3639)

The vulnerability allows a local attacker to obtain potentially sensitive information on the target system.

The weakness exists due to race conditions in CPU cache processing. A local attacker can conduct a side-channel attack to exploit a flaw in the speculative execution of Load and Store instructions to read privileged memory.

Note: the vulnerability is referred to as "Spectre variant 4".

Remediation

Install update from vendor's website.