Red Hat update for bash

1) Command injection

EUVDB-ID: #VU5295

Risk: Critical

CVSSv4.0: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Red]

CVE-ID: CVE-2014-6271

CWE-ID: CWE-77 - Command injection

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to execute arbitrary commands on the target system.

The vulnerability exists due to incorrect parsing of environment variables. A remote attacker can execute arbitrary code on the target system as demonstrated by vectors involving the ForceCommand feature in OpenSSH sshd, the mod_cgi and mod_cgid modules in the Apache HTTP Server, scripts executed by unspecified DHCP clients, and other situations in which setting the environment occurs across a privilege boundary from Bash execution.

Successful exploitation may allow an attacker to gain complete control over vulnerable system.

Exploitation example:

env x='() { :;}; echo vulnerable' bash -c "echo this is a test"

Note: this vulnerability was being actively exploited in the wild.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Red Hat Enterprise Linux EUS Compute Node: 7.3

Red Hat Enterprise Linux for Scientific Computing: 6 - 7

Red Hat Enterprise Linux for IBM z Systems: 6 - 7

Red Hat Enterprise Linux Desktop: 5 - 7

Red Hat Enterprise Linux Workstation: 6 - 7

Red Hat Enterprise Linux Server: v.5 - 7

CPE2.3

• cpe:2.3:o:red_hat:red_hat_enterprise_linux_eus_compute_node:7.3:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_scientific_computing:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_scientific_computing:7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_for_ibm_z_systems:7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_desktop:5:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_desktop:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_desktop:7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_workstation:6:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_workstation:7:*:*:*:*:red_hat_enterprise_linux:*:*
• cpe:2.3:o:red_hat:red_hat_enterprise_linux_server:v.5:*:*:*:*:red_hat_enterprise_linux:*:*

External links

https://access.redhat.com/errata/RHSA-2014:1293

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.