## Free Software Foundation statement on the GNU Bash "shellshock" vulnerability  

*This post can be viewed online at <https://fsf.org/news/free-software-foundation-statement-on-the-gnu-bash-shellshock-vulnerability>.*

A major security vulnerability has been discovered in the free
software shell GNU Bash. The most serious issues have already been
fixed, and a complete fix is well underway. GNU/Linux distributions
are working quickly to release updated packages for their users. All
Bash users should upgrade immediately, and audit the list of remote
network services running on their systems.

Bash is the [GNU Project's][1] shell; it is part of the suite of
software that makes up the GNU operating system. The GNU programs plus
the kernel Linux form a commonly used complete [free software][2]
operating system, called GNU/Linux. The bug, which is being referred
to as "shellshock," can allow, in some circumstances, attackers to
remotely access and control systems using Bash (and programs that call
Bash) as an attack vector, regardless of what kernel they are
running. The bug probably affects many GNU/Linux users, along with
those using Bash on proprietary operating systems like Apple's OS X
and Microsoft Windows. Additional technical details about the issue
can be found [at CVE-2014-6271][3] and [CVE-2014-7169][4].

[GNU Bash][5] has been widely adopted because it is a free (as in
freedom), reliable, and featureful shell. This popularity means the
serious bug that was published yesterday is just as
widespread. Fortunately, GNU Bash's license, the [GNU General Public
License version 3][6], has facilitated a rapid response. It allowed
[Red Hat][7] to develop and share patches in conjunction with Bash
upstream developers efforts to fix the bug, which anyone can download
and apply themselves. Everyone using Bash has the freedom to download,
inspect, and modify the code -- unlike with Microsoft, Apple, or other
proprietary software.

Software freedom is a precondition for secure computing; it guarantees
everyone the ability to examine the code to detect vulnerabilities,
and to create new and safe versions if a vulnerability is
discovered. Your software freedom does not guarantee bug-free code,
and neither does proprietary software: bugs happen no matter how the
software is licensed. But when a bug is discovered in free software,
everyone has the permission, rights, and source code to expose and fix
the problem. That fix can then be immediately freely distributed to
everyone who needs it. Thus, [these freedoms][2] are crucial for
ethical, secure computing.

Proprietary, (aka nonfree) software relies on an unjust development
model that denies users the basic freedom to control their
computers. When software's code is kept hidden, it is vulnerable not
only to bugs that go undetected, but to the easier deliberate addition
and maintenance of [malicious features][8]. Companies can use the
obscurity of their code to hide serious problems, and it has been
documented that [Microsoft provides intelligence agencies with
information about security vulnerabilities before fixing them][9].

Free software cannot guarantee your security, and in certain
situations may appear less secure on specific vectors than some
proprietary programs. As was widely agreed in the aftermath of the
OpenSSL "Heartbleed" bug, the solution is not to trade one security
bug for the very deep insecurity inherently created by proprietary
software -- the solution is to put energy and resources into auditing
and improving free programs.

Development of Bash, and GNU in general, is almost exclusively a
volunteer effort, and [you can contribute][5]. We are reviewing Bash
development, to see if increased funding can help prevent future
problems. If you or your organization use Bash and are potentially
interested in supporting its development, please [contact
us](donate@fsf.org).

The patches to fix this issue can be obtained directly at
<http://ftp.gnu.org/gnu/bash/>.

### Media Contacts

John Sullivan  
Executive Director  
Free Software Foundation  
+1 (617) 542 5942  
<campaigns@fsf.org> 

[1]: https://www.gnu.org
[2]: https://www.gnu.org/philosophy/free-sw
[3]: https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-6271
[4]: https://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2014-7169
[5]: https://www.gnu.org/software/bash/
[6]: https://www.gnu.org/licenses/gpl
[7]: https://securityblog.redhat.com/2014/09/24/bash-specially-crafted-environment-variables-code-injection-attack/
[8]: https://gnu.org/philosophy/proprietary
[9]: http://www.computerworlduk.com/blogs/open-enterprise/how-can-any-company-ever-trust-microsoft-again-3569376/