Amazon Linux AMI : kernel (ALAS-2016-703)

high Nessus Plugin ID 91241

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Synopsis

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

Description

The Linux kernel did not properly suppress hugetlbfs support in x86 PV guests, which could allow local PV guest users to cause a denial of service (guest OS crash) by attempting to access a hugetlbfs mapped area. (CVE-2016-3961 / XSA-174)

A flaw was found in the way the Linux kernel's ASN.1 DER decoder processed certain certificate files with tags of indefinite length. A local, unprivileged user could use a specially crafted X.509 certificate DER file to crash the system or, potentially, escalate their privileges on the system. (CVE-2016-0758)

Multiple race conditions in the ext4 filesystem implementation in the Linux kernel before 4.5 allow local users to cause a denial of service (disk corruption) by writing to a page that is associated with a different user's file after unsynchronized hole punching and page-fault handling. (CVE-2015-8839)

The following flaws were also fixed in this version :

CVE-2016-4557 : Use after free vulnerability via double fdput

CVE-2016-4581 : Slave being first propagated copy causes oops in propagate_mnt

CVE-2016-4486 : Information leak in rtnetlink

CVE-2016-4485 : Information leak in llc module

CVE-2016-4558 : bpf: refcnt overflow

CVE-2016-4565 : infiniband: Unprivileged process can overwrite kernel memory using rdma_ucm.ko

CVE-2016-0758 : tags with indefinite length can corrupt pointers in asn1_find_indefinite_length()

CVE-2015-8839 : ext4 filesystem page fault race condition with fallocate call.

Solution

Run 'yum update kernel' to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2016-703.html

Plugin Details

Severity: High

ID: 91241

File Name: ala_ALAS-2016-703.nasl

Version: 2.7

Type: local

Agent: unix

Published: 5/19/2016

Updated: 4/11/2019

Dependencies: ssh_get_info.nasl

Risk Information

VPR

Risk Factor: Critical

Score: 9.5

CVSS v2

Risk Factor: High

Base Score: 7.2

Temporal Score: 6

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

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

CVSS v3

Risk Factor: High

Base Score: 7.8

Temporal Score: 7.2

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

Temporal Vector: E:F/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-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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 5/18/2016

Exploitable With

Metasploit (Linux BPF doubleput UAF Privilege Escalation)

Reference Information

CVE: CVE-2015-8839, CVE-2016-0758, CVE-2016-3961, CVE-2016-4485, CVE-2016-4486, CVE-2016-4557, CVE-2016-4558, CVE-2016-4565, CVE-2016-4581

ALAS: 2016-703