8.6 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
0.972 High
EPSS
Percentile
99.8%
IBM SECURITY ADVISORY
First Issued: Fri Aug 21 15:48:15 CDT 2020
The most recent version of this document is available here:
http://aix.software.ibm.com/aix/efixes/security/bind_advisory17.asc
https://aix.software.ibm.com/aix/efixes/security/bind_advisory17.asc
ftp://aix.software.ibm.com/aix/efixes/security/bind_advisory17.asc
Security Bulletin: Vulnerabilities in BIND affect AIX (CVE-2020-8616 and
CVE-2020-8617)
===============================================================================
SUMMARY:
There are vulnerabilities in BIND that affect AIX.
===============================================================================
VULNERABILITY DETAILS:
CVEID: CVE-2020-8616
https://vulners.com/cve/CVE-2020-8616
https://vulners.com/cve/CVE-2020-8616
DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by the
failure to limit the number of fetches performed when processing
referrals. By using specially crafted referrals, a remote attacker
could exploit this vulnerability to cause the recursing server to
issue a very large number of fetches in an attempt to process the
referral.
CVSS Base Score: 8.6
CVSS Temporal Score: See
https://exchange.xforce.ibmcloud.com/vulnerabilities/182126
for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H)
CVEID: CVE-2020-8617
https://vulners.com/cve/CVE-2020-8617
https://vulners.com/cve/CVE-2020-8617
DESCRIPTION: ISC BIND is vulnerable to a denial of service, caused by a
logic error in code which checks TSIG validity. A remote attacker
could exploit this vulnerability to trigger an assertion failure in
tsig.c.
CVSS Base Score: 7.5
CVSS Temporal Score: See
https://exchange.xforce.ibmcloud.com/vulnerabilities/182127
for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
AFFECTED PRODUCTS AND VERSIONS:
AIX 7.1, 7.2
VIOS 2.2, 3.1
The following fileset levels are vulnerable:
key_fileset = aix
Fileset Lower Level Upper Level KEY
---------------------------------------------------------
bos.net.tcp.client 6.1.9.0 6.1.9.404 key_w_fs
bos.net.tcp.client 7.1.5.0 7.1.5.35 key_w_fs
bos.net.tcp.bind_utils 7.2.2.0 7.2.2.18 key_w_fs
bos.net.tcp.bind_utils 7.2.3.0 7.2.3.16 key_w_fs
bos.net.tcp.bind_utils 7.2.4.0 7.2.4.1 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
REMEDIATION:
A. APARS
IBM has assigned the following APARs to this problem:
AIX Level APAR Availability SP KEY
-----------------------------------------------------
7.1.5 IJ25924 ** SP07-2037 key_w_apar
7.2.2 IJ25925 ** N/A key_w_apar
7.2.3 IJ25926 ** SP06-2038 key_w_apar
7.2.4 IJ25927 ** SP03-2038 key_w_apar
VIOS Level APAR Availability SP KEY
----------------------------------------------------
2.2.6 IJ26021 ** N/A key_w_apar
3.1.0 IJ25926 ** 3.1.0.50 key_w_apar
3.1.1 IJ25927 ** 3.1.1.30 key_w_apar
Subscribe to the APARs here:
http://www.ibm.com/support/pages/apar/IJ25924
http://www.ibm.com/support/pages/apar/IJ25925
http://www.ibm.com/support/pages/apar/IJ25926
http://www.ibm.com/support/pages/apar/IJ25927
http://www.ibm.com/support/pages/apar/IJ26021
https://www.ibm.com/support/pages/apar/IJ25924
https://www.ibm.com/support/pages/apar/IJ25925
https://www.ibm.com/support/pages/apar/IJ25926
https://www.ibm.com/support/pages/apar/IJ25927
https://www.ibm.com/support/pages/apar/IJ26021
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/bind_fix17.tar
http://aix.software.ibm.com/aix/efixes/security/bind_fix17.tar
https://aix.software.ibm.com/aix/efixes/security/bind_fix17.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 (*.Z) KEY
----------------------------------------------
7.1.5.4 IJ25924s6a.200708.epkg.Z key_w_fix
7.1.5.5 IJ25924s6a.200708.epkg.Z key_w_fix
7.1.5.6 IJ25924s6a.200708.epkg.Z key_w_fix
7.2.2.4 IJ25925s6a.200708.epkg.Z key_w_fix
7.2.2.5 IJ25925s6a.200708.epkg.Z key_w_fix
7.2.2.6 IJ25925s6a.200708.epkg.Z key_w_fix
7.2.3.3 IJ25926s5a.200708.epkg.Z key_w_fix
7.2.3.4 IJ25926s5a.200708.epkg.Z key_w_fix
7.2.3.5 IJ25926s5a.200708.epkg.Z key_w_fix
7.2.4.0 IJ25927s2a.200708.epkg.Z key_w_fix
7.2.4.1 IJ25927s2a.200708.epkg.Z key_w_fix
7.2.4.2 IJ25927s2a.200708.epkg.Z key_w_fix
Please note that the above table refers to AIX TL/SP level as
opposed to fileset level, i.e., 7.2.3.5 is AIX 7200-03-05.
Please reference the Affected Products and Version section above
for help with checking installed fileset levels.
VIOS Level Interim Fix (*.Z) KEY
-----------------------------------------------
2.2.6.40 IJ26021sDa.200708.epkg.Z key_w_fix
2.2.6.41 IJ26021sDa.200708.epkg.Z key_w_fix
2.2.6.50 IJ26021sDa.200708.epkg.Z key_w_fix
2.2.6.51 IJ26021sDa.200708.epkg.Z key_w_fix
2.2.6.60 IJ26021sDa.200708.epkg.Z key_w_fix
2.2.6.61 IJ26021sDa.200708.epkg.Z key_w_fix
2.2.6.65 IJ26021sDa.200708.epkg.Z key_w_fix
3.1.0.20 IJ25926s5a.200708.epkg.Z key_w_fix
3.1.0.30 IJ25926s5a.200708.epkg.Z key_w_fix
3.1.0.40 IJ25926s5a.200708.epkg.Z key_w_fix
3.1.1.0 IJ25927s2a.200708.epkg.Z key_w_fix
3.1.1.10 IJ25927s2a.200708.epkg.Z key_w_fix
3.1.1.20 IJ25927s2a.200708.epkg.Z key_w_fix
3.1.1.21 IJ25927s2a.200708.epkg.Z key_w_fix
3.1.1.22 IJ25927s2a.200708.epkg.Z key_w_fix
3.1.1.25 IJ25927s2a.200708.epkg.Z key_w_fix
To extract the fixes from the tar file:
tar xvf bind_fix17.tar
cd bind_fix17
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
-----------------------------------------------------------------------------------------------------
1b952357d1691d203c13d888760553743269a7b84e3432131bab9a6a919a53a7 IJ25924s6a.200708.epkg.Z key_w_csum
5f221cb2ee211f02256d5e88c8a5962aed7a97ae6683a6eaf3724fe81eef0fe8 IJ25925s6a.200708.epkg.Z key_w_csum
e9b46105c1713fc1944b55fd3d637d912feaec439865bcc23a91c8f739ea5535 IJ25926s5a.200708.epkg.Z key_w_csum
d8a02e72780156eca420977627bb7c80455afc6e4b3d40a0e5cb5c6a72c4cfaa IJ25927s2a.200708.epkg.Z key_w_csum
974e499efc70808300e1e7bb7af7706765a6ccd040c5e76944a52b727c0f5dd7 IJ26021sDa.200708.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/bind_advisory17.asc.sig
https://aix.software.ibm.com/aix/efixes/security/bind_advisory17.asc.sig
ftp://aix.software.ibm.com/aix/efixes/security/bind_advisory17.asc.sig
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
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.
===============================================================================
CONTACT US:
Note: Keywords labeled as KEY in this document are used for parsing
purposes.
If you would like to receive AIX Security Advisories via email,
please visit "My Notifications":
http://www.ibm.com/support/mynotifications
To view previously issued advisories, please visit:
http://www14.software.ibm.com/webapp/set2/subscriptions/onvdq
Contact IBM Support for questions related to this announcement:
http://ibm.com/support/
https://ibm.com/support/
To obtain the OpenSSL public key that can be used to verify the
signed advisories and ifixes:
Download the key from our web page:
ftp://ftp.software.ibm.com/systems/power/AIX/systems_p_os_aix_security_pubkey.txt
Please contact your local IBM AIX support center for any
assistance.
REFERENCES:
Complete CVSS v3 Guide: http://www.first.org/cvss/user-guide
On-line Calculator v3:
http://www.first.org/cvss/calculator/3.0
RELATED INFORMATION:
IBM Secure Engineering Web Portal
http://www.ibm.com/security/secure-engineering/bulletins.html
IBM Product Security Incident Response Blog
https://www.ibm.com/blogs/psirt/
Security Bulletin: Vulnerabilities in BIND affect AIX
https://www.ibm.com/support/pages/node/6320325
ACKNOWLEDGEMENTS:
None.
CHANGE HISTORY:
First Issued: Fri Aug 21 15:48:15 CDT 2020
===============================================================================
*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.
8.6 High
CVSS3
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
NONE
User Interaction
NONE
Scope
CHANGED
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
5 Medium
CVSS2
Access Vector
NETWORK
Access Complexity
LOW
Authentication
NONE
Confidentiality Impact
NONE
Integrity Impact
NONE
Availability Impact
PARTIAL
AV:N/AC:L/Au:N/C:N/I:N/A:P
0.972 High
EPSS
Percentile
99.8%