SB2019073005 - Red Hat update for kernel



SB2019073005 - Red Hat update for kernel

Published: July 30, 2019

Security Bulletin ID SB2019073005
Severity
Medium
Patch available
YES
Number of vulnerabilities 5
Exploitation vector Remote access
Highest impact Code execution

Breakdown by Severity

Medium 20% Low 80%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 5 secuirty vulnerabilities.


1) Improper privilege management (CVE-ID: CVE-2017-12154)

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

The prepare_vmcs02 function in arch/x86/kvm/vmx.c in the Linux kernel through 4.13.3 does not ensure that the "CR8-load exiting" and "CR8-store exiting" L0 vmcs02 controls exist in cases where L1 omits the "use TPR shadow" vmcs12 control, which allows KVM L2 guest OS users to obtain read and write access to the hardware CR8 register.

2) Memory corruption (CVE-ID: CVE-2017-15129)

The vulnerability allows a local unprivileged attacker to cause DoS condition no the target system.

The weakness exists due to the function get_net_ns_by_id() in net/core/net_namespace.c does not check for the net::count value after it has found a peer network in netns_ids idr. A local attacker can induce kernel memory corruption, trigger use-after-free and double free error in network namespaces code to cause the system to crash.

3) NULL pointer dereference (CVE-ID: CVE-2017-15274)

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

The weakness exists in he security/keys/keyctl.c due to a NULL pointer dereference. A local attacker can create a specially crafted add_key or keyctl system call and cause a denial of service.

4) Information disclosure (CVE-ID: CVE-2018-3693)

The vulnerability allows a local attacker to obtain potentially sensitive information.

The vulnerability exists in the design of most modern CPUs using speculative execution and branch prediction due to improper speculative execution of instructions. A local attacker can bypass bounds checks, trigger buffer overflow, perform arbitrary speculative execution and a side-channel attack to access sensitive memory information.


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

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.

Remediation

Install update from vendor's website.