Amazon Linux AMI : kernel (ALAS-2016-726)

Medium Nessus Plugin ID 92661

Synopsis

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

Description

It was found that nfsd is missing permissions check when setting ACL on files, this may allow a local users to gain access to any file by setting a crafted ACL. (CVE-2016-1237)

A flaw was found in the Linux kernel's keyring handling code, where in key_reject_and_link() an uninitialised variable would eventually lead to arbitrary free address which could allow attacker to use a use-after-free style attack. (CVE-2016-4470)

A leak of information was possible when issuing a netlink command of the stack memory area leading up to this function call. An attacker could use this to determine stack information for use in a later exploit. (CVE-2016-5243)

A vulnerability was found in the Linux kernel in function rds_inc_info_copy of file net/rds/recv.c. The last field 'flags' of object 'minfo' is not initialized. This can leak data previously at the flags location to userspace. (CVE-2016-5244)

A flaw was found in the implementation of the Linux kernel's handling of networking challenge ack where an attacker is able to determine the shared counter which could be used to determine sequence numbers for TCP stream injection. (CVE-2016-5696)

(Updated on 2016-08-17: CVE-2016-5696 was fixed in this release but was not previously part of this errata)

Solution

Run 'yum update kernel' to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2016-726.html

Plugin Details

Severity: Medium

ID: 92661

File Name: ala_ALAS-2016-726.nasl

Version: 2.5

Type: local

Agent: unix

Published: 2016/08/02

Updated: 2018/04/18

Dependencies: 12634

Risk Information

Risk Factor: Medium

CVSS v2.0

Base Score: 5.8

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

CVSS v3.0

Base Score: 7.5

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

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: 2016/08/01

Reference Information

CVE: CVE-2016-1237, CVE-2016-4470, CVE-2016-5243, CVE-2016-5244, CVE-2016-5696

ALAS: 2016-726