Summary

There is a vulnerability in the rmsock command that affects AIX.

Vulnerability Details

CVEID: CVE-2018-1655 DESCRIPTION: IBM AIX contains a vulnerability in the rmsock command that may be used to expose kernel memory.
CVSS Base Score: 4
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/144748 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)

Affected Products and Versions

AIX 5.3, 6.1, 7.1, 7.2
VIOS 2.2.x

The vulnerabilities in the following filesets are being addressed:

key_fileset = aix

Fileset Lower Level Upper Level KEY
---------------------------------------------------------
bos.net.tcp.client 5.3.12.0 5.3.12.10 key_w_fs
bos.net.tcp.client 6.1.9.0 6.1.9.315 key_w_fs
bos.net.tcp.client 7.1.4.0 7.1.4.33 key_w_fs
bos.net.tcp.client 7.1.5.0 7.1.5.15 key_w_fs
bos.net.tcp.client_core 7.2.0.0 7.2.0.5 key_w_fs
bos.net.tcp.client_core 7.2.1.0 7.2.1.3 key_w_fs
bos.net.tcp.client_core 7.2.2.0 7.2.2.16 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 bos.net.tcp.client

Note: AIX or VIOS users of all fileset levels should continue to monitor their My Notifications alerts and the IBM PSIRT Blog for additional information about these vulnerabilities:

- My Notifications
http://www.ibm.com/support/mynotifications

Remediation/Fixes

A. APARS

IBM has assigned the following APARs to this problem:

AIX Level APAR Availability SP KEY

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

5.3.12 IJ06935 ** N/A key_w_apar

6.1.9 IJ06905 ** SP12 key_w_apar

7.1.4 IJ06906 ** SP7 key_w_apar

7.1.5 IJ06904 ** SP3 key_w_apar

7.2.0 IJ06934 ** N/A key_w_apar

7.2.1 IJ06907 ** SP5 key_w_apar

7.2.2 IJ06908 ** SP3 key_w_apar

VIOS Level APAR Availability SP KEY

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

2.2.4 IJ06905 ** N/A key_w_apar

2.2.5 IJ06905 ** 2.2.5.50 key_w_apar

2.2.6 IJ06905 ** 2.2.6.30 key_w_apar

Subscribe to the APARs here:

<http://www.ibm.com/support/docview.wss?uid=isg1IJ06904&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ06905&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ06906&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ06907&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ06908&gt;

<http://www.ibm.com/support/docview.wss?uid=isg1IJ06934&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ06904&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ06905&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ06906&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ06907&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ06908&gt;

<https://www.ibm.com/support/docview.wss?uid=isg1IJ06934&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/VIOS fixes can be downloaded via ftp or http from:

<ftp://aix.software.ibm.com/aix/efixes/security/rmsock_fix2.tar&gt;

<http://aix.software.ibm.com/aix/efixes/security/rmsock_fix2.tar&gt;

<https://aix.software.ibm.com/aix/efixes/security/rmsock_fix2.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

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

5.3.12.9 IJ06935s1a.180611.epkg.Z key_w_fix

6.1.9.9 IJ06905s9a.180608.epkg.Z key_w_fix

6.1.9.10 IJ06905s9a.180608.epkg.Z key_w_fix

6.1.9.11 IJ06905s9a.180608.epkg.Z key_w_fix

7.1.4.4 IJ06906s4a.180607.epkg.Z key_w_fix

7.1.4.5 IJ06906s4a.180607.epkg.Z key_w_fix

7.1.4.6 IJ06906s4a.180607.epkg.Z key_w_fix

7.1.5.0 IJ06904s5a.180607.epkg.Z key_w_fix

7.1.5.1 IJ06904s5a.180607.epkg.Z key_w_fix

7.1.5.2 IJ06904s5a.180607.epkg.Z key_w_fix

7.2.0.4 IJ06934s0a.180607.epkg.Z key_w_fix

7.2.0.5 IJ06934s0a.180607.epkg.Z key_w_fix

7.2.0.6 IJ06934s0a.180607.epkg.Z key_w_fix

7.2.1.2 IJ06907s1a.180607.epkg.Z key_w_fix

7.2.1.3 IJ06907s1a.180607.epkg.Z key_w_fix

7.2.1.4 IJ06907s1a.180607.epkg.Z key_w_fix

7.2.2.0 IJ06908s2a.180607.epkg.Z key_w_fix

7.2.2.1 IJ06908s2a.180607.epkg.Z key_w_fix

7.2.2.2 IJ06908s2a.180607.epkg.Z key_w_fix

Please note that the above table refers to AIX TL/SP level as opposed to fileset level, i.e., 7.2.2.2 is AIX 7200-02-02.

VIOS Level Interim Fix (*.Z) KEY

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

2.2.4.40 IJ06905s9a.180608.epkg.Z key_w_fix

2.2.4.50 IJ06905s9a.180608.epkg.Z key_w_fix

2.2.4.60 IJ06905s9a.180608.epkg.Z key_w_fix

2.2.5.20 IJ06905s9a.180608.epkg.Z key_w_fix

2.2.5.30 IJ06905s9a.180608.epkg.Z key_w_fix

2.2.5.40 IJ06905s9a.180608.epkg.Z key_w_fix

2.2.6.10 IJ06905s9a.180608.epkg.Z key_w_fix

2.2.6.20 IJ06905s9a.180608.epkg.Z key_w_fix

2.2.6.21 IJ06905s9a.180608.epkg.Z key_w_fix

To extract the fixes from the tar file:

tar xvf rmsock_fix2.tar

cd rmsock_fix2

Verify you have retrieved the fixes intact:

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

openssl dgst -sha256 filename KEY

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

ecf6f66a7b4b46d409d793f20040ee482483b1574171fb9359a923dd4895ab1a IJ06904s5a.180607.epkg.Z key_w_csum

c3c126553e839d9005e57b9c86c64ee9ec6bbaf2ab9a11a1999c5e513a27169c IJ06905s9a.180608.epkg.Z key_w_csum

c9853fd282018e3d4a7f43d7be2bdb8683e0b6fcafa030b0da3066071714a58b IJ06906s4a.180607.epkg.Z key_w_csum

d315a1422bad889b916b05bedd3f7a2017a6fd0cec92102bf82a4ae29097778e IJ06907s1a.180607.epkg.Z key_w_csum

1cf55bf5ba872df48e210a65d5d0830f08cff0173dc5cc6570be7b6a02268241 IJ06908s2a.180607.epkg.Z key_w_csum

b9ff613c66d80bb855808e2ef94a67d5643fd7587b134dc6a5619ac708c3a8d0 IJ06934s0a.180607.epkg.Z key_w_csum

1403b64ca4a545ef791460764a184d5a48a7112daec235474f070c5ff569e6cd IJ06935s1a.180611.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/&gt; 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/rmsock_advisory2.asc.sig&gt;

<https://aix.software.ibm.com/aix/efixes/security/rmsock_advisory2.asc.sig&gt;

<ftp://aix.software.ibm.com/aix/efixes/security/rmsock_advisory2.asc.sig&gt;

C. 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&gt;

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.