Date: Wed, 14 Aug 2002 10:21:01 -0700 (PDT)
From: SGI Security Coordinator <[email protected]>
To: [email protected]Subject: Acrobat Reader symlink vulnerability on IRIX
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_____________________________________________________________________________
SGI Security Advisory
Title: Acrobat Reader symlink vulnerability
Number: 20020806-01-I
Date: August 14, 2002
Reference: CAN-2001-1069
_____________________________________________________________________________
- -----------------------
- --- Issue Specifics ---
- -----------------------
It's been reported that the 4.05 version of Adobe's Acrobat Reader
("acroread") supplied with IRIX 6.5 creates insecure temporary files:
http://online.securityfocus.com/archive/1/277932/2002-06-17/2002-06-23/0
This is considered to be a low risk vulnerability open to the possibility
of a symlink attack.
SGI has investigated the issue and recommends the following steps for
neutralizing the exposure. It is HIGHLY RECOMMENDED that these measures be
implemented on ALL vulnerable SGI systems.
These issues have been corrected in future releases of IRIX.
- --------------
- --- Impact ---
- --------------
The /usr/bin/acroread binary is not installed by default on IRIX 6.5
systems, it is part of the optional acrobat.sw.reader package supplied on
the IRIX Applications CD.
To determine the version of IRIX you are running, execute the following
command:
# uname -R
That will return a result similar to the following:
# 6.5 6.5.16f
The first number ("6.5") is the release name, the second ("6.5.16f" in this
case) is the extended release name. The extended release name is the
"version" we refer to throughout this document.
To see if acroread is installed, execute the following command:
$ versions acrobat.sw.reader
I = Installed, R = Removed
Name Date Description
I acrobat 09/19/2000 Adobe Acrobat Reader, 4.05
I acrobat.sw 09/19/2000 Acrobat Reader Software, 4.05
I acrobat.sw.reader 09/19/2000 Acrobat Reader, 4.05
If the output shows that version 4.05 of the software is installed, the
system is vulnerable.
This vulnerability was assigned the following CVE:
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2001-1069
- ----------------------------
- --- Temporary Workaround ---
- ----------------------------
SGI will release an updated Acrobat Reader package on the Applications CD as
shipped with IRIX 6.5.19. If you want to protect yourself until updating to
6.5.19, or if you simply cannot update to 6.5.19, then installing the
following script will afford you the same protection:
First rename /usr/adobe/Acrobat4.0/bin/acroread to acroread.dist:
# mv /usr/adobe/Acrobat4.0/bin/acroread
/usr/adobe/Acrobat4.0/bin/acroread.dist
Then insert the following script in its place:
------- cut here -----
#!/bin/sh -fb
# Acrobat Reader 4.05 (acroread) creates temporary files in /tmp (or
# in directory pointed by TMP environment variable) insecurely when
# opening or printing a PDF document. If we use /tmp malicious users
# could craft symlinks that caused files to be overwritten.
PROG="/usr/adobe/Acrobat4.0/bin/acroread.dist"
MYTMP="${HOME}/.acrobat"
export TMPDIR=$MYTMP;
export TMP=$MYTMP;
# Create the new ~/.acroread temporary directory if necessary.
# Let users symlink it to another location if they want.
# Since the link is in their home directory it should be as
# trustworthy as anything else.
if [ ! -e $MYTMP ]; then
/bin/mkdir -m 700 $MYTMP || exit $?
fi
exec $PROG ${1+"$@"}
------- cut here -----
Install that script as /usr/adobe/Acrobat4.0/bin/acroread
Don't forget to:
# chmod 755 /usr/adobe/Acrobat4.0/bin/acroread
- ----------------
- --- Solution ---
- ----------------
SGI has not provided patches for this vulnerability. Our recommendation is
to upgrade to IRIX 6.5.19 when it becomes available or use the wrapper
script workaround shown above.
OS Version Vulnerable? Patch # Other Actions
---------- ----------- ------- -------------
IRIX 3.x unknown Note 1
IRIX 4.x unknown Note 1
IRIX 5.x unknown Note 1
IRIX 6.0.x unknown Note 1
IRIX 6.1 unknown Note 1
IRIX 6.2 unknown Note 1
IRIX 6.3 unknown Note 1
IRIX 6.4 unknown Note 1
IRIX 6.5 yes Note 2
IRIX 6.5.1 yes Note 2
IRIX 6.5.2 yes Note 2
IRIX 6.5.3 yes Note 2
IRIX 6.5.4 yes Note 2
IRIX 6.5.5 yes Note 2
IRIX 6.5.6 yes Note 2
IRIX 6.5.7 yes Note 2
IRIX 6.5.8 yes Note 2
IRIX 6.5.9 yes Note 2
IRIX 6.5.10 yes Note 2
IRIX 6.5.11 yes Note 2
IRIX 6.5.12 yes Note 2
IRIX 6.5.13 yes Note 2
IRIX 6.5.14 yes Note 2
IRIX 6.5.15 yes Note 2
IRIX 6.5.16 yes Note 2
IRIX 6.5.17 yes Note 2
IRIX 6.5.18 yes Note 2
IRIX 6.5.19 no
NOTES
1) This version of the IRIX operating has been retired. Upgrade to an
actively supported IRIX operating system. See
http://support.sgi.com/irix/news/index.html#policy for more
information.
2) Use the wrapper shown above.
- -------------
- --- Links ---
- -------------
SGI Security Advisories can be found at:
http://www.sgi.com/support/security/ and
ftp://patches.sgi.com/support/free/security/advisories/
SGI Security Patches can be found at:
http://www.sgi.com/support/security/ and
ftp://patches.sgi.com/support/free/security/patches/
SGI patches for IRIX can be found at the following patch servers:
http://support.sgi.com/irix/ and ftp://patches.sgi.com/
SGI freeware updates for IRIX can be found at:
http://freeware.sgi.com/
SGI fixes for SGI open sourced code can be found on:
http://oss.sgi.com/projects/
SGI patches and RPMs for Linux can be found at:
http://support.sgi.com/linux/ or
http://oss.sgi.com/projects/sgilinux-combined/download/security-fixes/
SGI patches for Windows NT or 2000 can be found at:
http://support.sgi.com/nt/
IRIX 5.2-6.4 Recommended/Required Patch Sets can be found at:
http://support.sgi.com/irix/ and ftp://patches.sgi.com/support/patchset/
IRIX 6.5 Maintenance Release Streams can be found at:
http://support.sgi.com/colls/patches/tools/relstream/index.html
IRIX 6.5 Software Update CDs can be obtained from:
http://support.sgi.com/irix/swupdates/
The primary SGI anonymous FTP site for security advisories and patches is
patches.sgi.com (216.32.174.211). Security advisories and patches are
located under the URL ftp://patches.sgi.com/support/free/security/
For security and patch management reasons, ftp.sgi.com (mirrors
patches.sgi.com security FTP repository) lags behind and does not do a
real-time update.
- ------------------------
- --- Acknowledgments ----
- ------------------------
SGI wishes to thank FIRST and the users of the Internet Community at large
for their assistance in this matter.
- -----------------------------------------
- --- SGI Security Information/Contacts ---
- -----------------------------------------
If there are questions about this document, email can be sent to
[email protected].
------oOo------
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______________________________________________________________________________
This information is provided freely to all interested parties
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