SB2018100511 - Amazon Linux AMI update for kernel



SB2018100511 - Amazon Linux AMI update for kernel

Published: October 5, 2018 Updated: October 23, 2018

Security Bulletin ID SB2018100511
CSH Severity
Medium
Patch available
YES
Number of vulnerabilities 3
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 33% Low 67%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 3 vulnerabilities.


1) Buffer over-read (CVE-ID: CVE-2018-16658)

CWE-ID: CWE-125 - Out-of-bounds read

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


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

The vulnerability exists due to a boundary condition in cdrom_ioctl_drive_status() function in drivers/cdrom/cdrom.c. A local unprivileged user can create a specially crafted application, trigger out-of-bounds read error and read contents of kernel memory.


2) Stack-based buffer overflow (CVE-ID: CVE-2018-14633)

CWE-ID: CWE-121 - Stack-based buffer overflow

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green


The vulnerability allows a remote attacker to execute arbitrary code on the target system.
The vulnerability exists due to a boundary error when processing client digest packets in chap_server_compute_md5() function when processing authentication request from an ISCSI initiator. A remote attacker can send an overly long value (longer than 32 bytes), trigger stack-based buffer overflow and execute arbitrary code on the target system.

3) Use-after-free (CVE-ID: CVE-2018-17182)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


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

The vulnerability exists due to a use-after-free error in vmacache_flush_all() function in mm/vmacache.c file. A local user can trigger the use-after-free error via certain thread creation, map, unmap, invalidation, and dereference operations and execute arbitrary code on the system with elevated privileges.


Remediation

Install update from vendor's website.