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Security Bulletin: IBM has released AIX and VIOS iFixes in response to a vulnerability in IBM POWER9 (CVE-2020-4788)

Security Bulletin


Summary

IBM has released the following fixes for AIX and VIOS in response to CVE-2020-4788.

Vulnerability Details

CVEID:   CVE-2020-4788
DESCRIPTION:   IBM Power9 processors could allow a local user to obtain sensitive information from the data in the L1 cache under extenuating circumstances.
CVSS Base score: 5.1
CVSS Temporal Score: See: https://exchange.xforce.ibmcloud.com/vulnerabilities/189296 for the current score.
CVSS Vector: (CVSS:3.0/AV:L/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)

Affected Products and Versions

Affected Product(s) Version(s)
AIX 7.1
AIX 7.2
VIOS 3.1

The vulnerabilities in the following filesets are being addressed:

Fileset  Lower Level  Upper Level 
bos.mp64  7.1.5.0  7.1.5.40 
bos.mp64  7.2.3.0  7.2.3.19 
bos.mp64  7.2.4.0  7.2.4.6 
bos.mp64  7.2.5.0  7.2.5.1

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.mp64

Remediation/Fixes

A. APARS

IBM has assigned the following APARs to this problem:

AIX Level  APAR  SP 
7.1.5  IJ28229  SP08 
7.2.3  IJ28228  SP07 
7.2.4  IJ28227  SP04 
7.2.5  IJ28226  SP02
VIOS Level  APAR  SP 
3.1.0  IJ28228  3.1.0.60 
3.1.1  IJ28227  3.1.1.40 
3.1.2  IJ28226  3.1.2.20

Subscribe to the APARs here:
https://www.ibm.com/support/pages/apar/IJ28226
https://www.ibm.com/support/pages/apar/IJ28227
https://www.ibm.com/support/pages/apar/IJ28228
https://www.ibm.com/support/pages/apar/IJ28229

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.

An LPAR system reboot is required to complete the iFix installation, or Live Update may be used on AIX 7.2 to avoid a reboot.

The AIX and VIOS fixes can be downloaded via ftp or http from:
ftp://aix.software.ibm.com/aix/efixes/security/power9_fix.tar
http://aix.software.ibm.com/aix/efixes/security/power9_fix.tar
https://aix.software.ibm.com/aix/efixes/security/power9_fix.tar

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 
7.1.5.5 

IJ28229s5a.200921.epkg.Z

7.1.5.5

IJ28229s5b.200922.epkg.Z

7.1.5.6 

IJ28229s6a.200921.epkg.Z

7.1.5.6 

IJ28229s6b.200922.epkg.Z

7.1.5.6

IJ28229s6c.200922.epkg.Z

7.1.5.7

IJ28229s7a.201117.epkg.Z

7.1.5.7

IJ28229s7b.201117.epkg.Z

7.2.3.3 

IJ28228s3a.200921.epkg.Z

7.2.3.4

IJ28228s4a.200921.epkg.Z

7.2.3.5

IJ28228s5a.200921.epkg.Z

7.2.4.0

IJ28227s0a.200922.epkg.Z

7.2.4.1

IJ28227s1a.200922.epkg.Z

7.2.4.2

IJ28227s2a.200922.epkg.Z

7.2.4.2

IJ28227s2b.200922.epkg.Z

7.2.4.2

IJ28227s2c.200922.epkg.Z

7.2.5.0 

IJ28226s1b.201117.epkg.Z

7.2.5.1 

IJ28226s1a.201117.epkg.Z

Please note that the above table refers to AIX TL/SP level as opposed to fileset level, i.e., 7.2.3.5 is AIX 7200-03-05.

NOTE:  Multiple iFixes are provided for AIX 7100-05-05, 7100-05-06, 7100-05-07, and 7200-04-02.
IJ28229s5a is for AIX 7100-05-05 with bos.mp64 fileset level 7.1.5.35.
IJ28229s5b is for AIX 7100-05-05 with bos.mp64 fileset level 7.1.5.34.
IJ28229s6a is for AIX 7100-05-06 with bos.mp64 fileset level 7.1.5.38.
IJ28229s6b is for AIX 7100-05-06 with bos.mp64 fileset level 7.1.5.37.
IJ28229s6c is for AIX 7100-05-06 with bos.mp64 fileset level 7.1.5.36.
IJ28229s7a is for AIX 7100-05-07 with bos.mp64 fileset level 7.1.5.40.
IJ28229s7b is for AIX 7100-05-07 with bos.mp64 fileset level 7.1.5.39.
IJ28227s2a is for AIX 7200-04-02 with bos.mp64 fileset level 7.2.4.6.
IJ28227s2b is for AIX 7200-04-02 with bos.mp64 fileset level 7.2.4.4.
IJ28227s2c is for AIX 7200-04-02 with bos.mp64 fileset level 7.2.4.3.

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

 VIOS Level Interim Fix 
3.1.0.20 

IJ28228s3a.200921.epkg.Z

3.1.0.30 

IJ28228s4a.200921.epkg.Z

3.1.0.40 

IJ28228s5a.200921.epkg.Z

3.1.1.0 

IJ28227s0a.200922.epkg.Z

3.1.1.10 

IJ28227s1a.201205.epkg.Z

3.1.1.20 

IJ28227s2c.200922.epkg.Z

3.1.1.21

IJ28227s2b.200922.epkg.Z

3.1.1.25 

IJ28227s2a.200922.epkg.Z

3.1.2.0 

IJ28226s1b.201117.epkg.Z

3.1.2.10 

IJ28226s1a.201117.epkg.Z

To extract the fixes from the tar file:

tar xvf power9_fix.tar
cd power9_fix

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 

7b7e42cbe9d554d367b0b1e7c835f00acf56542494ba2335c99d2ab5bf0e8a90

IJ28226s1a.201117.epkg.Z

917d14f1de9d035bb886832c0699318f8d7375229cd023b918f6cbd52f7d32c8

IJ28226s1b.201117.epkg.Z

f0c4d9afcb04e50c2136571cc71a1cc9be5af3f59255f2d8715ac2ae484bb946

IJ28227s0a.200922.epkg.Z

e8c72d5ed5390822100650cb070f202ec5acb04b837137a89a8f752291f5932d

IJ28227s1a.200922.epkg.Z

5f346c251953846f58b844d5094013d2252d452058cb5da224f36a528d17ede0

IJ28227s1a.201205.epkg.Z

7e0cf61c13075097fe8b0cee502d720502e98e1a123c3296f34f15300f90eea3

IJ28227s2a.200922.epkg.Z

877fe90f3400c78a2f3b77725c7b691efc295c9bf3feb88745bafdd8c88f3bd7

IJ28227s2b.200922.epkg.Z

a1b4860075e719f38f815555c58fccb375e0eec9494893b3c58f4f0cbf8e8ae4

IJ28227s2c.200922.epkg.Z

25b098e2e46401d76764da722c9e188b63e20f421528df6be39a97fc953f7fb1

IJ28228s3a.200921.epkg.Z

f7d43a6ac69315919a1aa0d95315fb75a346f9108d43e49e31c6fc9442fff66f

IJ28228s4a.200921.epkg.Z

386be2edbaad3eb83d5d40c0e36284c0a572d560f976f46fd1060af25f13e5fe

IJ28228s5a.200921.epkg.Z 

9848255e82e0b2c2d1106a2d1f5d788eb511bb5e635256e7d6d6a65a746e7822

IJ28229s4a.200921.epkg.Z

f2365acc12ee821cddf1ffb30e94b03c334472384f03bedb41144766326bea22 

IJ28229s5a.200921.epkg.Z

986822400bff40e2f28c8bf084e4e7474e6b7529ea2a8993c63d6294cd7419d3

IJ28229s5b.200922.epkg.Z

cf2cf1d43a23fca5ad47d9b53a5aa16cedd4338238abb82cc4b7e36c4b981d92 

IJ28229s6a.200921.epkg.Z

3d95fc39119f8910f4ac652b771524c64866b44552285816a1297b2e33ca6b6c

IJ28229s6b.200922.epkg.Z

f96bae09f77e0ca2c6d116623acb8a247f98e974a0036dbf01e17d39dca4a328 

IJ28229s6c.200922.epkg.Z 

d1de12482295ef395c0d26892820b71f2e0e4184a4cfd9d8fd4cff2da6c9fa7b 

IJ28229s7a.201117.epkg.Z

36d43d4560d2a7aca52aeb2d8615635c2e4d76bb92d5d4698ccc8e21ffd8448c

IJ28229s7b.201117.epkg.Z

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/power9_advisory.asc.sig
https://aix.software.ibm.com/aix/efixes/security/power9_advisory.asc.sig
ftp://aix.software.ibm.com/aix/efixes/security/power9_advisory.asc.sig 

C. FIX AND INTERIM FIX INSTALLATION

An LPAR system reboot is required to complete the iFix installation, or Live Update may be used on AIX 7.2 to avoid a reboot.

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

Get Notified about Future Security Bulletins

References

Off

Acknowledgement

Anthony Steinhauser of Google's Safeside Project

Change History

18 Nov 2020: Initial Publication

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.

Document Location

Worldwide

[{"Business Unit":{"code":"BU009","label":"Systems - Server"},"Product":{"code":"SWG10","label":"AIX"},"Component":"","Platform":[{"code":"PF002","label":"AIX"}],"Version":"7.1,7.2","Edition":""}]

Document Information

Modified date:
08 December 2020

UID

ibm16370729