Amazon Linux AMI : bash (ALAS-2017-878)

High Nessus Plugin ID 102866

Synopsis

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

Description

popd controlled free :

A denial of service flaw was found in the way bash handled popd commands. A poorly written shell script could cause bash to crash resulting in a local denial of service limited to a specific bash session.(CVE-2016-9401)

Arbitrary code execution via malicious hostname :

An arbitrary command injection flaw was found in the way bash processed the hostname value. A malicious DHCP server could use this flaw to execute arbitrary commands on the DHCP client machines running bash under specific circumstances.(CVE-2016-0634)

Specially crafted SHELLOPTS+PS4 variables allows command substitution :

An arbitrary command injection flaw was found in the way bash processed the SHELLOPTS and PS4 environment variables. A local, authenticated attacker could use this flaw to exploit poorly written setuid programs to elevate their privileges under certain circumstances. (CVE-2016-7543)

Solution

Run 'yum update bash' to update your system.

See Also

https://alas.aws.amazon.com/ALAS-2017-878.html

Plugin Details

Severity: High

ID: 102866

File Name: ala_ALAS-2017-878.nasl

Version: 3.2

Type: local

Agent: unix

Published: 2017/09/01

Updated: 2018/04/18

Dependencies: 12634

Risk Information

Risk Factor: High

CVSS v2.0

Base Score: 7.2

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

CVSS v3.0

Base Score: 8.4

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

Vulnerability Information

CPE: p-cpe:/a:amazon:linux:bash, p-cpe:/a:amazon:linux:bash-debuginfo, p-cpe:/a:amazon:linux:bash-doc, cpe:/o:amazon:linux

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

Patch Publication Date: 2017/08/31

Reference Information

CVE: CVE-2016-0634, CVE-2016-7543, CVE-2016-9401

ALAS: 2017-878