Summary

There is a vulnerability in Xorg that affects AIX.

Vulnerability Details

CVEID: CVE-2018-14665 DESCRIPTION: X.Org X server could allow a remote authenticated attacker to gain elevated privileges on the system, caused by improper validation of command line parameters. An attacker could exploit this vulnerability using the -modulepath argument or the -logfile argument to overwrite arbitrary files and execute unprivileged code on the system.
CVSS Base Score: 8.8
CVSS Temporal Score: See <https://exchange.xforce.ibmcloud.com/vulnerabilities/151991&gt; for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)

Affected Products and Versions

AIX 6.1, 7.1, 7.2
VIOS 2.2.x

The following fileset levels are vulnerable:

key_fileset = aix

Fileset Lower Level Upper Level KEY
---------------------------------------------------------
X11.base.rte 6.1.9.0 6.1.9.100 key_w_fs
X11.base.rte 7.1.4.0 7.1.4.31 key_w_fs
X11.base.rte 7.1.5.0 7.1.5.31 key_w_fs
X11.base.rte 7.2.0.0 7.2.0.1 key_w_fs
X11.base.rte 7.2.1.0 7.2.1.0 key_w_fs
X11.base.rte 7.2.2.0 7.2.2.16 key_w_fs
X11.base.rte 7.2.3.0 7.2.3.15 key_w_fs

To find out whether the affected filesets are installed on your systems, refer to the lslpp command found in AIX user’s guide.

Example: lslpp -L | grep -i X11.base.rte

Remediation/Fixes

A. APARS

IBM has assigned the following APARs to this problem:

AIX Level APAR Availability SP KEY

------------------------------------------------

6.1.9 IJ11000 ** N/A key_w_apar

7.1.4 IJ11544 ** SP08 key_w_apar

7.1.5 IJ11545 ** SP04 key_w_apar

7.2.0 IJ11546 ** N/A key_w_apar

7.2.1 IJ11547 ** SP06 key_w_apar

7.2.2 IJ11549 ** SP04 key_w_apar

7.2.3 IJ11550 ** SP03 key_w_apar

VIOS Level APAR Availability SP KEY

----------------------------------------------------

2.2.4 IJ11000 ** N/A key_w_apar

2.2.5 IJ11000 ** 2.2.5.60 key_w_apar

2.2.6 IJ11000 ** 2.2.6.40 key_w_apar

3.1.0 IJ11550 ** 3.1.0.20 key_w_apar

Subscribe to the APARs here:

<http://www.ibm.com/support/docview.wss?uid=isg1IJ11000&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ11544&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ11545&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ11546&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ11547&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ11549&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ11550&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ11000&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ11544&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ11545&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ11546&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ11547&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ11549&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ11550&gt;

By subscribing, you will receive periodic email alerting you to the status of the APAR, and a link to download the fix once it becomes available.

B. FIXES

AIX and VIOS fixes are available.

The AIX and VIOS fixes can be downloaded via ftp or http from:

<ftp://aix.software.ibm.com/aix/efixes/security/xorg_fix3.tar&gt;

<http://aix.software.ibm.com/aix/efixes/security/xorg_fix3.tar&gt;

<https://aix.software.ibm.com/aix/efixes/security/xorg_fix3.tar&gt;

The link above is to a tar file containing this signed advisory, fix packages, and OpenSSL signatures for each package. The fixes below include prerequisite checking. This will enforce the correct mapping between the fixes and AIX Technology Levels.

AIX Level Interim Fix (*.Z) KEY
----------------------------------------------
6.1.9.x IJ11000s0b.181127.epkg.Z key_w_fix
7.1.4.4 IJ11544s0a.181127.epkg.Z key_w_fix
7.1.4.5 IJ11544s0a.181127.epkg.Z key_w_fix
7.1.4.6 IJ11544s0a.181127.epkg.Z key_w_fix
7.1.4.7 IJ11544s0a.190312.epkg.Z key_w_fix
7.1.5.0 IJ11544s0a.181127.epkg.Z key_w_fix
7.1.5.1 IJ11544s0a.181127.epkg.Z key_w_fix
7.1.5.2 IJ11544s0a.181127.epkg.Z key_w_fix
7.1.5.3 IJ11544s0a.181127.epkg.Z key_w_fix
7.1.5.3 IJ11545s0a.181127.epkg.Z key_w_fix
7.2.0.x IJ11546s0a.181127.epkg.Z key_w_fix
7.2.1.x IJ11547s0a.181127.epkg.Z key_w_fix
7.2.2.0 IJ11549s0a.181127.epkg.Z key_w_fix
7.2.2.1 IJ11549s0a.181127.epkg.Z key_w_fix
7.2.2.2 IJ11549s0a.181127.epkg.Z key_w_fix
7.2.2.3 IJ11549s0a.190312.epkg.Z key_w_fix
7.2.3.x IJ11550s0a.181127.epkg.Z key_w_fix

Please reference the Affected Products and Version section above for help with checking installed fileset levels.

NOTE: Multiple iFixes are provided for AIX 7100-05-03.
IJ11544s0a is for AIX 7100-05-03 with X11.base.rte fileset level 7.1.4.30.
IJ11545s0a is for AIX 7100-05-03 with X11.base.rte fileset level 7.1.5.31.

VIOS Level Interim Fix (*.Z) KEY

-----------------------------------------------

2.2.x IJ11000s0b.181127.epkg.Z key_w_fix

3.1.x IJ11550s0a.181127.epkg.Z key_w_fix

To extract the fixes from the tar file:

tar xvf xorg_fix3.tar

cd xorg_fix3

Verify you have retrieved the fixes intact:

The checksums below were generated using the “openssl dgst -sha256 [filename]” command as the following:

openssl dgst -sha256 filename KEY
-----------------------------------------------------------------------------------------------------
81a407e154ab90e003135bf075f171b127d811e3a9177cb866d589ff2459ef19 IJ11000s0b.181127.epkg.Z key_w_csum
458f8391ceabeedf418f54595ce9ef87d63a667369dc4a3112b8548bff80fb6d IJ11544s0a.181127.epkg.Z key_w_csum
2b719e0b4d8bdcb89f97ffe1ecceccfbf0538cb2cdec66b8214eeae7c7b37958 IJ11544s0a.190312.epkg.Z key_w_csum
041e1271b858211365025a4528c71f453c72405a1f0809128e0c70d49886a166 IJ11545s0a.181127.epkg.Z key_w_csum
1f4f7a7ef34c7804464ccdc02f1a253ac373a9c66ee3144350b390509976cfad IJ11546s0a.181127.epkg.Z key_w_csum
8aac56821f52600ee3158efa39e0bf697813712364b946c199fbb32dd1da9ce6 IJ11547s0a.181127.epkg.Z key_w_csum
7518d581224e6b4332b4cfab48253a7427fb0e3ab866567766b2d137bc0e9267 IJ11549s0a.181127.epkg.Z key_w_csum
0eea9877dcaf6ffbd6c0d7572fd7ceb6437ef1f0b2f3134a22afc47260e9e7c5 IJ11549s0a.190312.epkg.Z key_w_csum
f18e4f2efd4f488e7a02de90bfa6992b604298dba1d588689d4e58e71b3738db IJ11550s0a.181127.epkg.Z key_w_csum

These sums should match exactly. The OpenSSL signatures in the tar file and on this advisory can also be used to verify the integrity of the fixes. If the sums or signatures cannot be confirmed, contact IBM Support at http://ibm.com/support/ and describe the discrepancy.

openssl dgst -sha1 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file]

openssl dgst -sha1 -verify [pubkey_file] -signature [ifix_file].sig [ifix_file]

Published advisory OpenSSL signature file location:

http://aix.software.ibm.com/aix/efixes/security/xorg_advisory3.asc.sig
https://aix.software.ibm.com/aix/efixes/security/xorg_advisory3.asc.sig
ftp://aix.software.ibm.com/aix/efixes/security/xorg_advisory3.asc.sig

FIX AND INTERIM FIX INSTALLATION

If possible, it is recommended that a mksysb backup of the system be created. Verify it is both bootable and readable before proceeding.

To preview a fix installation:

installp -a -d fix_name -p all # where fix_name is the name of the

fix package being previewed.

To install a fix package:

installp -a -d fix_name -X all # where fix_name is the name of the

fix package being installed.

Interim fixes have had limited functional and regression testing but not the full regression testing that takes place for Service Packs; however, IBM does fully support them.

Interim fix management documentation can be found at:

http://www14.software.ibm.com/webapp/set2/sas/f/aix.efixmgmt/home.html

To preview an interim fix installation:

emgr -e ipkg_name -p # where ipkg_name is the name of the

interim fix package being previewed.

To install an interim fix package:

emgr -e ipkg_name -X # where ipkg_name is the name of the

interim fix package being installed.

Workarounds and Mitigations

None.