There are vulnerabilities in BIND that impact AIX.,There are vulnerabilities in BIND that impact VIOS.

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.

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    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.