ถือว่าเป็น bug ที่กระทบกับระบบ linux และ unix ที่ใช้งานตัว bash shell กันครับ
ซึ่งทาง Redhat เองแนะนำให้อัฟเดทเลย เพื่อป้องกันไม่ให้ตกเป็นเป้า อิอิ
Because of its wide distribution, the vulnerability could be as wide-ranging as the Heartbleed bug, though it may not be nearly as dangerous. The vulnerability affects versions 1.14 through 4.3 of GNU Bash. Patches have been issued by many of the major Linux distribution vendors for affected versions, including:
Red Hat Enterprise Linux (versions 4 through 7) and the Fedora distribution
CentOS (versions 5 through 7)
Ubuntu 10.04 LTS, 12.04 LTS, and 14.04 LTS
Debian
A test on Mac OS X 10.9.4 ("Mavericks") by Ars showed that it also has a vulnerable version of Bash. Apple has not yet patched Bash, though it just issued an update to "command line tools."
While Bash is often thought of just as a local shell, it is also frequently used by Apache servers to execute CGI scripts for dynamic content (through mod_cgi and mod_cgid). A crafted web request targeting a vulnerable CGI application could launch code on the server. Similar attacks are possible via OpenSSH, which could allow even restricted secure shell sessions to bypass controls and execute code on the server. And a malicious DHCP server set up on a network or running as part of an “evil” wireless access point could execute code on some Linux systems using the Dynamic Host Configuration Protocol client (dhclient) when they connect.
There are other services that run on Linux and Unix systems, such as the CUPS printing system, that are similarly dependent on Bash that could be vulnerable.
There is an easy test to determine if a Linux or Unix system is vulnerable. To check your system, from a command line, type:
#env x='() { :;}; echo vulnerable' bash -c "echo this is a test"
If the system is vulnerable, the output will be:
vulnerable
this is a test
An unaffected (or patched) system will output:
bash: warning: x: ignoring function definition attempt
bash: error importing function definition for `x'
this is a test
###CentOS
#yum update
bash x86_64 version : 4.1.2-15.el6_5.1
###Reference
http://arstechnica.com/security/2014/09/bug-in-bash-shell-creates-big-security-hole-on-anything-with-nix-in-it/
