Amazon Linux AMI : kernel (ALAS-2018-1086)

high Nessus Plugin ID 117923
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Synopsis

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

Description

A security flaw was found in the chap_server_compute_md5() function in the ISCSI target code in the Linux kernel in a way an authentication request from an ISCSI initiator is processed. An unauthenticated remote attacker can cause a stack buffer overflow and smash up to 17 bytes of the stack. The attack requires the iSCSI target to be enabled on the victim host. Depending on how the target's code was built (i.e.
depending on a compiler, compile flags and hardware architecture) an attack may lead to a system crash and thus to a denial-of-service or possibly to a non-authorized access to data exported by an iSCSI target. Due to the nature of the flaw, privilege escalation cannot be fully ruled out, although we believe it is highly unlikely.(CVE-2018-14633)

An information leak was discovered in the Linux kernel in cdrom_ioctl_drive_status() function in drivers/cdrom/cdrom.c that could be used by local attackers to read kernel memory at certain location.(CVE-2018-16658)

A security flaw was discovered in the Linux kernel. The vmacache_flush_all() function in mm/vmacache.c mishandles sequence number overflows. An attacker can trigger a use-after-free (and possibly gain privileges) via certain thread creation, map, unmap, invalidation, and dereference operations.(CVE-2018-17182)

A flaw was found in the Linux kernels block driver implementation (blk_drain_queue() function) where a use-after-free condition could be triggered while draining the outstanding command queue in the systems block device subsystem. An attacker could use this flaw to crash the system or corrupt local memory, which may lead to privilege escalation.(CVE-2018-20856)

Solution

Run 'yum update kernel' and reboot your instance to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2018-1086.html

Plugin Details

Severity: High

ID: 117923

File Name: ala_ALAS-2018-1086.nasl

Version: 1.6

Type: local

Agent: unix

Published: 10/5/2018

Updated: 6/4/2020

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: High

Score: 7.4

CVSS v2

Risk Factor: High

Base Score: 8.3

Temporal Score: 6.5

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

Temporal Vector: E:POC/RL:OF/RC:C

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7

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

Temporal Vector: E:P/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 Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 6/3/2020

Vulnerability Publication Date: 9/7/2018

Reference Information

CVE: CVE-2018-14633, CVE-2018-16658, CVE-2018-17182, CVE-2018-20856

ALAS: 2018-1086