Re: : [Security] Update bash *NOW*
William Muriithi <[email protected]> Thu, 25 Sep 2014 10:50:54 -0400
| Newsgroups | gmane.org.user-groups.linux.tolug |
|---|---|
| Message-ID | <[email protected]> |
=E2=80=8EYa, Seem all over news. If you are managing public git through gitolite, you may want to look at it= asap. William=C2=A0 =C2=A0 Original Message =C2=A0 From: Walter Dnes Sent: Wednesday, September 24, 2014 10:04 PM To: Toronto Linux Users Group Reply To: [email protected] Subject: [TLUG]: [Security] Update bash *NOW* Slashdot article http://linux.slashdot.org/story/14/09/24/1638207/remote-ex= ploit-vulnerability-found-in-bash Story at http://www.csoonline.com/article/2687265/application-security/remo= te-exploit-in-bash-cve-2014-6271.html CVE ID CVE-2014-6271 at http://seclists.org/oss-sec/2014/q3/650 Summary... bash scripts, CGI, perl via "system()", and various other "commands" invoke a bash shell at times, passing environmental variables in the process. Problem is that an "environmental variable" ***CAN CONTAIN A FUNCTION DEFINITION, AND EXECUTE IT WHILST SPAWNING A NEW SHELL***. E.g. execute the command... env x=3D'() { :;}; echo vulnerable' bash -c "echo this is a test" ...and you get the following... vulnerable this is a test Replace... x=3D'() { :;}; echo vulnerable' ...with malicious stuff, and it could get ugly. bash-4.2_p48 seems to fix this security hole. The same "env" command results in... bash: warning: x: ignoring function definition attempt bash: error importing function definition for `x' this is a test --=20 Walter Dnes <waltdnes-SLHPyeZ9y/[email protected]> I don't run "desktop environments"; I run useful applications -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists -- The Toronto Linux Users Group. Meetings: http://gtalug.org/ TLUG requests: Linux topics, No HTML, wrap text below 80 columns How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists