CVE-2021-38995: Security Bulletin: Vulnerabilities in the AIX kernel (CVE-2021-38994, CVE-2021-38995)

Security Bulletin

Summary

There are multiple vulnerabilities in the AIX kernel.

Vulnerability Details

Affected Products and Versions

Affected Product(s)

Version(s)

AIX

7.1

AIX

7.2

AIX

7.3

VIOS

3.1

The vulnerabilities in the following filesets are being addressed:

Fileset

Lower Level

Upper Level

bos.mp64

7.1.5.0

7.1.5.45

bos.mp64

7.2.4.0

7.2.4.9

bos.mp64

7.2.5.0

7.2.5.3

bos.mp64

7.2.5.100

7.2.5.103

bos.mp64

7.3.0.0

7.3.0.1

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

IJ37452

SP10

7.2.4

IJ37501

SP06

7.2.5

IJ37012

SP04

7.3.0

IJ37001

SP02

VIOS Level

APAR

SP

3.1.1

IJ37501

3.1.1.60

3.1.2

IJ37776

3.1.2.40

3.1.3

IJ37012

3.1.3.20

Subscribe to the APARs here:

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:

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

7.1.5.7

IJ37452m7a.220215.epkg.Z

7.1.5.8

IJ37452m8a.220215.epkg.Z

7.1.5.9

IJ37452s9a.220215.epkg.Z

7.1.5.9

IJ37452s9b.220215.epkg.Z

7.2.4.3

IJ37501m3a.220215.epkg.Z

7.2.4.4

IJ37501m4a.220215.epkg.Z

7.2.4.5

IJ37501m5a.220215.epkg.Z

7.2.5.1

IJ37776m1a.220215.epkg.Z

7.2.5.2

IJ37776m2a.220215.epkg.Z

7.2.5.3

IJ37012m3a.220215.epkg.Z

7.2.5.3

IJ37012m3b.220215.epkg.Z

7.3.0.1

IJ37001m1a.220215.epkg.Z

Please note that the above table refers to AIX TL/SP level as opposed to fileset level, i.e., 7.2.5.2 is AIX 7200-05-02.

NOTE: Multiple iFixes are provided for AIX 7100-05-09 and 7200-05-03.

IJ37452s9a is for AIX 7100-05-09 with bos.mp64 fileset level 7.1.5.45.

IJ37452s9b is for AIX 7100-05-09 with bos.mp64 fileset level 7.1.5.44.

IJ37012m3a is for AIX 7200-05-03 with bos.mp64 fileset level 7.2.5.103.

IJ37012m3b is for AIX 7200-05-03 with bos.mp64 fileset level 7.2.5.101.

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

VIOS Level

Interim Fix

3.1.1.30

IJ37501m3a.220215.epkg.Z

3.1.1.40

IJ37501m4a.220215.epkg.Z

3.1.1.50

IJ37501m5a.220215.epkg.Z

3.1.2.10

IJ37776m1a.220215.epkg.Z

3.1.2.21

IJ37776m2a.220215.epkg.Z

3.1.3.10

IJ37012m3b.220215.epkg.Z

3.1.3.14

IJ37012m3a.220215.epkg.Z

The fixes are cumulative and address previously issued AIX/VIOS kernel security bulletins with respect to SP and TL, which includes:

To extract the fixes from the tar file:

tar xvf kernel_fix3.tar

cd kernel_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

10e4ef561cfb0e44a698948eaa3f157c1fbdd22dc6b9095898f813e4e306fa55

IJ37001m1a.220215.epkg.Z

70e53abb9b1b60222a215b04373a79c315d003d5f174f9e1b2fa521bd3201c35

IJ37012m3a.220215.epkg.Z

b575eff5b745fabc369477cec9408e35bfac445d77835ed4df4836ca56fb7cf0

IJ37012m3b.220215.epkg.Z

7c3c4f2aaa7a3624066785211735decfe33bef38c01dff62c3c075f0c4ba535a

IJ37452m7a.220215.epkg.Z

328b6d14775423691f5c3b746367e9fdbd24b71230195b93124e2066be499dc4

IJ37452m8a.220215.epkg.Z

6ffa2ad6d1dff2252b4cc5f6e7dfc1a83d15dedc44e0d35f69bfd7b01aab39b8

IJ37452s9a.220215.epkg.Z

e4c7fffdc340a122e42e3a1ce73a6f20ccf0d045dcd4958bc82b69b08add18d8

IJ37452s9b.220215.epkg.Z

ba1c1b1fbe6c1f6a68b6dd48d0f5e61221751d288e8bb141c5e4c2b806322044

IJ37501m3a.220215.epkg.Z

f0dc84ce2145a301b8e7ddbc0e6335bc93fe6468fafb67dd3b67bf73b535c5df

IJ37501m4a.220215.epkg.Z

467d4747459d37489b2199d57836de3d79a3837b95c2aa29dc35f43fe33bd0ed

IJ37501m5a.220215.epkg.Z

9acb84e45fa3aa0b8d36e9f63d29dcc0e335c0d55351a2a5b8433bd57075dc01

IJ37776m1a.220215.epkg.Z

30e03d25a0657290afb9c04ac1b5b06fd87a8a776dfe037b2d5dd9b92e16c7cd

IJ37776m2a.220215.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 -sha256 -verify [pubkey_file] -signature [advisory_file].sig [advisory_file]

openssl dgst -sha256 -verify [pubkey_file] -signature [ifix_file].sig [ifix_file]

Published advisory OpenSSL signature file location:

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:

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

References

Off

Change History

23 Feb 2022: 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

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