Amazon Linux AMI : kernel (ALAS-2017-925)

High Nessus Plugin ID 104707

Synopsis

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

Description

Incorrect updates of uninstantiated keys crash the kernel

A vulnerability was found in the key management subsystem of the Linux kernel. An update on an uninstantiated key could cause a kernel panic, leading to denial of service (DoS). (CVE-2017-15299)

Memory leak when merging buffers in SCSI IO vectors

It was found that in the Linux kernel through v4.14-rc5, bio_map_user_iov() and bio_unmap_user() in 'block/bio.c' do unbalanced pages refcounting if IO vector has small consecutive buffers belonging to the same page. bio_add_pc_page() merges them into one, but the page reference is never dropped, causing a memory leak and possible system lockup due to out-of-memory condition. (CVE-2017-12190)

NULL pointer dereference due to incorrect node-splitting in assoc_array implementation

A flaw was found in the Linux kernel's implementation of associative arrays introduced in 3.13. This functionality was backported to the 3.10 kernels in Red Hat Enterprise Linux 7. The flaw involved a NULL pointer dereference in assoc_array_apply_edit() due to incorrect node-splitting in assoc_array implementation. This affects the keyring key type and thus key addition and link creation operations may cause the kernel to panic. (CVE-2017-12193)

Arbitrary stack overwrite causing oops via crafted signal frame

A flaw was found in the Linux kernel's handling of signal frame on PowerPC systems. A malicious local user process could craft a signal frame allowing an attacker to corrupt memory. (CVE-2017-1000255)

Race condition in the KEYS subsystem

The KEYS subsystem in the Linux kernel before 4.13.10 does not correctly synchronize the actions of updating versus finding a key in the 'negative' state to avoid a race condition, which allows local users to cause a denial of service or possibly have unspecified other impact via crafted system calls. (CVE-2017-15951)

Solution

Run 'yum update kernel' to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2017-925.html

Plugin Details

Severity: High

ID: 104707

File Name: ala_ALAS-2017-925.nasl

Version: 3.3

Type: local

Agent: unix

Published: 2017/11/21

Modified: 2018/04/18

Dependencies: 12634

Risk Information

Risk Factor: High

CVSSv2

Base Score: 7.2

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

CVSSv3

Base Score: 7.8

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

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-doc, 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

Patch Publication Date: 2017/11/18

Reference Information

CVE: CVE-2017-1000255, CVE-2017-12190, CVE-2017-12193, CVE-2017-15299, CVE-2017-15951

ALAS: 2017-925