SB2019012922 - Red Hat update for kernel
Published: January 29, 2019
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 secuirty vulnerabilities.
1) Security restrictions bypass (CVE-ID: CVE-2018-18397)
The vulnerability allows a local attacker to bypass security restrictions on the target system.
The vulnerability exists due to improper access control in the userfaultfd implementation. A local attacker can access a system that is mounted with shmem or hugetlbs virtual memory areas, maliciously modify mapping to targeted files and write arbitrary memory on the system, which could be used to conduct additional attacks.
2) Privilege escalation (CVE-ID: CVE-2018-18559)
The vulnerability allows a local attacker to gain elevated privileges on the target system.
The vulnerability exists due to improper handling of a certain multithreaded case involving packet_do_bind unregister and packet_notifier register actions after a race condition between fanout_add, from setsockopt, and a bind on an AF_PACKET socket. A local attacker can execute a program or file that submits malicious input, trigger a use-after-free condition and execute arbitrary code with kernel privileges.
Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.
Remediation
Install update from vendor's website.