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* [gentoo-user] [Security] Update bash *NOW*
@ 2014-09-25  1:58 Walter Dnes
  2014-09-25 12:54 ` Kerin Millar
  0 siblings, 1 reply; 6+ messages in thread
From: Walter Dnes @ 2014-09-25  1:58 UTC (permalink / raw
  To: Gentoo Users List

  Slashdot article http://linux.slashdot.org/story/14/09/24/1638207/remote-exploit-vulnerability-found-in-bash

  Story at http://www.csoonline.com/article/2687265/application-security/remote-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='() { :;}; echo vulnerable' bash -c "echo this is a test"

...and you get the following...

vulnerable
this is a test

  Replace...

x='() { :;}; echo vulnerable'

...with malicious stuff, and it could get ugly.  app-shells/bash-4.2_p48
has been pushed to Gentoo stable.  The same "env" command results in...

bash: warning: x: ignoring function definition attempt
bash: error importing function definition for `x'
this is a test


-- 
Walter Dnes <waltdnes@waltdnes.org>
I don't run "desktop environments"; I run useful applications


^ permalink raw reply	[flat|nested] 6+ messages in thread

end of thread, other threads:[~2014-09-26  0:11 UTC | newest]

Thread overview: 6+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2014-09-25  1:58 [gentoo-user] [Security] Update bash *NOW* Walter Dnes
2014-09-25 12:54 ` Kerin Millar
2014-09-25 12:58   ` Kerin Millar
2014-09-25 14:02   ` covici
2014-09-25 14:09     ` Tomas Mozes
2014-09-26  0:11   ` Walter Dnes

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