Amazon Linux 2 : kernel (ALAS-2020-1566)

high Nessus Plugin ID 143589

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Synopsis

The remote Amazon Linux 2 host is missing a security update.

Description

The version of kernel installed on the remote host is prior to 4.14.209-160.335. It is, therefore, affected by multiple vulnerabilities as referenced in the ALAS2-2020-1566 advisory.

A use-after-free flaw was found in the debugfs_remove function in the Linux kernel. The flaw could allow a local attacker with special user (or root) privilege to crash the system at the time of file or directory removal. This vulnerability can lead to a kernel information leak. The highest threat from this vulnerability is to system availability. (CVE-2019-19770)

A flaw was found in the Linux kernel. A use-after-free memory flaw was found in the perf subsystem allowing a local attacker with permission to monitor perf events to corrupt memory and possibly escalate privileges. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability. (CVE-2020-14351)

A flaw was found in the Linux kernel. A use-after-free was found in the way the console subsystem was using ioctls KDGKBSENT and KDSKBSENT. A local user could use this flaw to get read memory access out of bounds. The highest threat from this vulnerability is to data confidentiality. (CVE-2020-25656)

A flaw was found in Linux Kernel because access to the global variable fg_console is not properly synchronized leading to a use after free in con_font_op. (CVE-2020-25668)

The function sunkbd_reinit having been scheduled by sunkbd_interrupt before sunkbd being freed.Though the dangling pointer is set to NULL in sunkbd_disconnect, there is still a alias in sunkbd_reinit so that causing Use After Free. (CVE-2020-25669)

A flaw memory leak in the Linux kernel performance monitoring subsystem was found in the way if using PERF_EVENT_IOC_SET_FILTER. A local user could use this flaw to starve the resources causing denial of service. (CVE-2020-25704)

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x. Guest OS users can cause a denial of service (host OS hang) via a high rate of events to dom0, aka CID-e99502f76271.
(CVE-2020-27673)

An issue was discovered in the Linux kernel through 5.9.1, as used with Xen through 4.14.x.
drivers/xen/events/events_base.c allows event-channel removal during the event-handling loop (a race condition). This can cause a use-after-free or NULL pointer dereference, as demonstrated by a dom0 crash via events for an in-reconfiguration paravirtualized device, aka CID-073d0552ead5. (CVE-2020-27675)

The Linux kernel for powerpc has an issue with the Run-Time Abstraction Services (RTAS) interface, allowing root (or CAP_SYS_ADMIN users) in a VM to overwrite some parts of memory, including kernel memory.This issue impacts guests running on top of PowerVM or KVM hypervisors (pseries platform), and does
*not* impact bare-metal machines (powernv platform). (CVE-2020-27777)

An issue was discovered in drivers/accessibility/speakup/spk_ttyio.c in the Linux kernel through 5.9.9.
Local attackers on systems with the speakup driver could cause a local denial of service attack, aka CID-d41227544427. This occurs because of an invalid free when the line discipline is used more than once.
(CVE-2020-28941)

A slab-out-of-bounds read in fbcon in the Linux kernel before 5.9.7 could be used by local attackers to read privileged information or potentially crash the kernel, aka CID-3c4e0dff2095. This occurs because KD_FONT_OP_COPY in drivers/tty/vt/vt.c can be used for manipulations such as font height. (CVE-2020-28974)

A flaw was found in the Linux kernel's implementation of Intel's Running Average Power Limit (RAPL) implementation. A local attacker could infer secrets by measuring power usage and also infer private data by observing the power usage of calculations performed on the data. (CVE-2020-8694)

Tenable has extracted the preceding description block directly from the tested product security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Run 'yum update kernel' to update your system.

Plugin Details

Severity: High

ID: 143589

File Name: al2_ALAS-2020-1566.nasl

Version: 1.8

Type: local

Agent: unix

Family: Amazon Linux Local Security Checks

Published: 12/9/2020

Updated: 12/11/2024

Supported Sensors: Agentless Assessment, Continuous Assessment, Frictionless Assessment Agent, Frictionless Assessment AWS, Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.7

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 5.6

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

CVSS Score Source: CVE-2020-27777

CVSS v3

Risk Factor: High

Base Score: 8.2

Temporal Score: 7.4

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

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

CVSS Score Source: CVE-2019-19770

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:perf, p-cpe:/a:amazon:linux:perf-debuginfo, p-cpe:/a:amazon:linux:kernel-tools-debuginfo, p-cpe:/a:amazon:linux:kernel-debuginfo-common-aarch64, p-cpe:/a:amazon:linux:kernel-tools, p-cpe:/a:amazon:linux:kernel-devel, p-cpe:/a:amazon:linux:python-perf-debuginfo, p-cpe:/a:amazon:linux:kernel, p-cpe:/a:amazon:linux:kernel-debuginfo, p-cpe:/a:amazon:linux:kernel-headers, p-cpe:/a:amazon:linux:kernel-livepatch-4.14.209-160.335, cpe:/o:amazon:linux:2, p-cpe:/a:amazon:linux:kernel-tools-devel, p-cpe:/a:amazon:linux:kernel-debuginfo-common-x86_64, p-cpe:/a:amazon:linux:python-perf

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 12/8/2020

Vulnerability Publication Date: 12/12/2019

Reference Information

CVE: CVE-2019-19770, CVE-2020-14351, CVE-2020-25656, CVE-2020-25668, CVE-2020-25669, CVE-2020-25704, CVE-2020-27673, CVE-2020-27675, CVE-2020-27777, CVE-2020-28941, CVE-2020-28974, CVE-2020-8694

ALAS: 2020-1566

Detections

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