It lands countless websites, servers, PCs, OS X Macs, various home routers, and more, in danger of hijacking by hackers.It puts Apache web servers, in particular, at risk of compromise: CGI scripts that use or invoke Bash in any way – including any child processes spawned by the scripts – are vulnerable to remote-code injection. OpenSSH and some DHCP clients are also affected on machines that use Bash.
The National Vulnerability Database detailed the following issues
- Summary: GNU Bash through 4.3 bash43-026 does not properly parse function definitions in the values of environment variables, which allows remote attackers to execute arbitrary commands via a crafted environment, 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. NOTE: this vulnerability exists because of an incomplete fix for CVE-2014-6271, CVE-2014-7169, and CVE-2014-6277.Published: 9/30/2014 6:55:04 AMCVSS Severity: 10.0 HIGH
Consensus opinion on new media at this time: where the system is exposed to such risk (you are using bash shell) update bash to the latest version,download the patched updates when they become available.Mitigate risk with internal,external operational audit and risk assessment.http://ftp.gnu.org/gnu/bash/bash-4.3-patches/
Using Apache servers
Blogs and websiteshttp://www.symantec.com/connect/blogs/shellshock-all-you-need-know-about-bash-bug-vulnerabilityhttp://tools.cisco.com/security/center/viewAlert.x?alertId=35845