CentOS 5 / 6 / 7 : bash (CESA-2014:1293) (Shellshock)

critical Nessus Plugin ID 77835

Synopsis

The remote CentOS host is missing one or more security updates.

Description

Updated bash packages that fix one security issue are now available for Red Hat Enterprise Linux 5, 6, and 7.

Red Hat Product Security has rated this update as having Critical security impact. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available from the CVE link in the References section.

The GNU Bourne Again shell (Bash) is a shell and command language interpreter compatible with the Bourne shell (sh). Bash is the default shell for Red Hat Enterprise Linux.

A flaw was found in the way Bash evaluated certain specially crafted environment variables. An attacker could use this flaw to override or bypass environment restrictions to execute shell commands. Certain services and applications allow remote unauthenticated attackers to provide environment variables, allowing them to exploit this issue.
(CVE-2014-6271)

For additional information on the CVE-2014-6271 flaw, refer to the Knowledgebase article at https://access.redhat.com/articles/1200223

Red Hat would like to thank Stephane Chazelas for reporting this issue.

All bash users are advised to upgrade to these updated packages, which contain a backported patch to correct this issue.

Solution

Update the affected bash packages.

See Also

http://www.nessus.org/u?218f06b1

http://www.nessus.org/u?f85a2dec

http://www.nessus.org/u?93307af1

http://www.nessus.org/u?3adf2ea1

Plugin Details

Severity: Critical

ID: 77835

File Name: centos_RHSA-2014-1293.nasl

Version: 1.30

Type: local

Agent: unix

Published: 9/25/2014

Updated: 1/31/2022

Supported Sensors: Frictionless Assessment Agent, Frictionless Assessment AWS, Frictionless Assessment Azure

Risk Information

VPR

Risk Factor: Critical

Score: 9.5

CVSS v2

Risk Factor: Critical

Base Score: 10

Temporal Score: 8.7

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

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

CVSS Score Source: CVE-2014-6271

CVSS v3

Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9.4

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

Temporal Vector: E:H/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:centos:centos:bash, p-cpe:/a:centos:centos:bash-doc, cpe:/o:centos:centos:5, cpe:/o:centos:centos:6, cpe:/o:centos:centos:7

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/24/2014

Vulnerability Publication Date: 9/24/2014

CISA Known Exploited Dates: 7/28/2022

Exploitable With

Core Impact

Metasploit (Qmail SMTP Bash Environment Variable Injection (Shellshock))

Reference Information

CVE: CVE-2014-6271

RHSA: 2014:1293

IAVA: 2014-A-0142