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Bug 625893 - (CVE-2011-1095) CVE-2011-1095 glibc: insufficient quoting in the locale command output
CVE-2011-1095 glibc: insufficient quoting in the locale command output
Status: CLOSED ERRATA
Product: Security Response
Classification: Other
Component: vulnerability (Show other bugs)
unspecified
All Linux
low Severity low
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Assigned To: Red Hat Product Security
public=20100811,reported=20100820,sou...
: Security
Depends On: 688214 688215 688217 688219 767685 769360
Blocks: 767564
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Reported: 2010-08-20 14:00 EDT by Vincent Danen
Modified: 2016-02-04 01:47 EST (History)
6 users (show)

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Doc Type: Bug Fix
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Last Closed: 2012-02-13 15:54:53 EST
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Description Vincent Danen 2010-08-20 14:00:07 EDT
Harald van Dijk discovered [1],[2] that glibc's locale command does not sufficiently sanitize the user environment.  According to POSIX specifications [3], the output of the 'locale' command must be appropriately quoted and safe to execute, in order to restore the locale after temporarily forcing a change (such as LC_ALL=C).  However, this is not the case with glibc versions up to and including 2.12.1:

LANG=' rm -rf /' locale
locale: Cannot set LC_CTYPE to default locale: No such file or directory
locale: Cannot set LC_MESSAGES to default locale: No such file or directory
locale: Cannot set LC_ALL to default locale: No such file or directory
LANG= rm -rf /
LC_CTYPE=" rm -rf /"
LC_NUMERIC=" rm -rf /"
LC_TIME=" rm -rf /"
LC_COLLATE=" rm -rf /"
LC_MONETARY=" rm -rf /"
LC_MESSAGES=" rm -rf /"
LC_PAPER=" rm -rf /"
LC_NAME=" rm -rf /"
LC_ADDRESS=" rm -rf /"
LC_TELEPHONE=" rm -rf /"
LC_MEASUREMENT=" rm -rf /"
LC_IDENTIFICATION=" rm -rf /"
LC_ALL=

Any script that does "eval $(locale)" or something similar will execute the unquoted commands.

The POSIX specification states:

"The <value> and <implied value> shown above shall be properly quoted for possible later reentry to the shell. The <value> shall not be quoted using double-quotes (so that it can be distinguished by the user from the <implied value> case, which always requires double-quotes)."

This has been corrected upstream [4].

[1] http://bugs.gentoo.org/show_bug.cgi?id=330923
[2] http://sources.redhat.com/bugzilla/show_bug.cgi?id=11904
[3] http://www.opengroup.org/onlinepubs/000095399/utilities/locale.html
[4] http://sourceware.org/git/?p=glibc.git;a=patch;h=026373745eab50a683536d950cb7e17dc98c4259
Comment 2 Tomas Hoger 2011-02-07 08:19:44 EST
Is there any real world example where this bug actually allows crossing trust boundary?  I was not able to find any use where this "eval $(locale)" pattern is used even with trusted environment.  Additionally, glibc locale man page does not document POSIX requirement to have the output safe for re-entry to the shell.

I don't think this got any CVE assigned either.  Gentoo GLSA 201011-01 does link their bug listed in comment #1 as [1], but the issue is not described in the text.

http://www.gentoo.org/security/en/glsa/glsa-201011-01.xml
Comment 4 errata-xmlrpc 2011-04-04 16:06:14 EDT
This issue has been addressed in following products:

  Red Hat Enterprise Linux 5

Via RHSA-2011:0412 https://rhn.redhat.com/errata/RHSA-2011-0412.html
Comment 5 errata-xmlrpc 2011-04-04 16:22:15 EDT
This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2011:0413 https://rhn.redhat.com/errata/RHSA-2011-0413.html
Comment 8 errata-xmlrpc 2012-02-13 15:35:35 EST
This issue has been addressed in following products:

  Red Hat Enterprise Linux 4

Via RHSA-2012:0125 https://rhn.redhat.com/errata/RHSA-2012-0125.html
Comment 9 Vincent Danen 2012-02-13 15:54:42 EST
Statement:

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