Amazon Linux AMI : kernel (ALAS-2020-1360)

Medium Nessus Plugin ID 135936

Synopsis

The remote Amazon Linux AMI host is missing a security update.

Description

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.
(CVE-2020-8648)

A flaw was found in the way KVM hypervisor handled instruction emulation for the L2 guest when nested(=1) virtualization is enabled.
In the instruction emulation, the L2 guest could trick the L0 hypervisor into accessing sensitive bits of the L1 hypervisor. An L2 guest could use this flaw to potentially access information of the L1 hypervisor. (CVE-2020-2732)

A stack buffer overflow issue was found in the get_raw_socket() routine of the Host kernel accelerator for virtio net (vhost-net) driver. It could occur while doing an ictol(VHOST_NET_SET_BACKEND) call, and retrieving socket name in a kernel stack variable via get_raw_socket(). A user able to perform ioctl(2) calls on the '/dev/vhost-net' device may use this flaw to crash the kernel resulting in DoS issue. (CVE-2020-10942)

Solution

Run 'yum update kernel' to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2020-1360.html

Plugin Details

Severity: Medium

ID: 135936

File Name: ala_ALAS-2020-1360.nasl

Version: 1.3

Type: local

Agent: unix

Published: 2020/04/24

Updated: 2020/04/30

Dependencies: 12634

Risk Information

Risk Factor: Medium

CVSS Score Source: CVE-2020-10942

CVSS v2.0

Base Score: 5.4

Temporal Score: 4

Vector: CVSS2#AV:L/AC:M/Au:N/C:N/I:P/A:C

Temporal Vector: CVSS2#E:U/RL:OF/RC:C

CVSS v3.0

Base Score: 5.3

Temporal Score: 4.6

Vector: CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:H

Temporal Vector: CVSS:3.0/E:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-i686, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:kernel-headers, p-cpe:/a:amazon:linux:kernel-tools, p-cpe:/a:amazon:linux:kernel-tools-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:perf, p-cpe:/a:amazon:linux:perf-debuginfo, cpe:/o:amazon:linux

Required KB Items: Host/local_checks_enabled, Host/AmazonLinux/release, Host/AmazonLinux/rpm-list

Exploit Ease: No known exploits are available

Patch Publication Date: 2020/04/23

Vulnerability Publication Date: 2020/02/06

Reference Information

CVE: CVE-2020-10942, CVE-2020-2732, CVE-2020-8648

ALAS: 2020-1360