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SECURITY (Doc Number=5014): Vulnerabilities in OpenSSH affect AIX

SECURITY (Doc Number=5014): Vulnerabilities in OpenSSH affect AIX
IBM SECURITY ADVISORY

First Issued: Thu Sep  8 14:36:37 CDT 2016

The most recent version of this document is available here:

http://aix.software.ibm.com/aix/efixes/security/openssh_advisory9.asc
https://aix.software.ibm.com/aix/efixes/security/openssh_advisory9.asc
ftp://aix.software.ibm.com/aix/efixes/security/openssh_advisory9.asc

Security Bulletin:  Vulnerabilities in OpenSSH affect AIX (CVE-2015-8325,
CVE-2016-6210 and CVE-2016-6515)
    
    
===============================================================================

SUMMARY:

Vulnerabilities in OpenSSH affect AIX
    
    
===============================================================================

VULNERABILITY DETAILS:

    CVEID: CVE-2015-8325
    DESCRIPTION: When the UseLogin feature is enabled and PAM is configured to 
        read .pam_environment files in user home directories, allows local users

        to gain privileges by triggering a crafted environment for the
/bin/login 
        program, as demonstrated by an LD_PRELOAD environment variable.
    CVSS Base Score: 7.4
    CVSS Temporal Score: See
        https://exchange.xforce.ibmcloud.com/vulnerabilities/114628 for the 
        current score.
    CVSS Environmental Score*: Undefined
    CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)
    
    CVEID: CVE-2016-6210
    DESCRIPTION: An attacker can measure timing differences in password 
    authentication that could be used to discern valid from invalid account 
    names when long passwords were sent and particular password hashing
       algorithms are in use on the server 
    CVSS Base Score: 4.3
    CVSS Temporal Score: See
        https://exchange.xforce.ibmcloud.com/vulnerabilities/115128 for the 
        current score.
    CVSS Environmental Score*: Undefined
    CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)
    
    CVEID: CVE-2016-6515
    DESCRIPTION: sshd does not limit password lengths for password
authentication, 
        which allows remote attackers to cause a denial of service 
        (crypt CPU consumption) via a long string.  
    CVSS Base Score: 7.5 
    CVSS Temporal Score: See
        https://exchange.xforce.ibmcloud.com/vulnerabilities/115911 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 VERSION:
    
        AIX 5.3, 6.1, 7.1, 7.2
        VIOS 2.2.x
        
        The following fileset levels are vulnerable:
        
        key_fileset = osrcaix
        
        Fileset                 Lower Level   Upper Level    KEY
        -------------------------------------------------------------
        openssh.base.client     4.0.0.5200    6.0.0.6202     key_w_fs
        openssh.base.server     4.0.0.5200    6.0.0.6202     key_w_fs
   
        Note:  To determine if your system is vulnerable, execute the
        following commands:

            lslpp -L | grep -i openssh.base.client
            lslpp -L | grep -i openssh.base.server

        
    REMEDIATION:

        A. FIXES

            Fixes are available.  The fixes can be downloaded via ftp and
            http from:

            ftp://aix.software.ibm.com/aix/efixes/security/openssh_fix9.tar
            http://aix.software.ibm.com/aix/efixes/security/openssh_fix9.tar
            https://aix.software.ibm.com/aix/efixes/security/openssh_fix9.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
            releases.

            Note that the tar file contains Interim fixes that are based on
            OpenSSH version as given below - 

            You must be on the 'prereq for installation' level before
            applying the interim fix. This may require installing a new
            level(prereq version) first.
            

        AIX Level           Interim Fix (*.Z)        
        Fileset Name(prereq for installation) KEY
        -----------------------------------------------
        ---------------------------------------------
        5.3, 6.1, 7.1, 7.2  6202_ifix.160830.epkg.Z 
        openssh.base(6.0.0.6202 version)      key_w_fix

        VIOS Level     Interim Fix (*.Z)         
        Fileset Name(prereq for installation) KEY
        ---------------------------------------------
        -------------------------------------------
        2.2.*          6202_ifix.160830.epkg.Z  
        openssh.base(6.0.0.6202 version)      key_w_fix


            Latest level of OpenSSH fileset is available from the web download
site:
            https://www14.software.ibm.com/webapp/iwm/web
/reg/download.do?source=aixbp⟨=en_US&S_PKG=openssh&cp=UTF-8

           
            To extract the fix from the tar file:

            tar xvf openssh_fix9.tar
            cd openssh_fix9

            Verify you have retrieved the fix intact:

            The checksums below were generated using the
            "openssl dgst -sha256 file" command is the followng:

        openssl dgst -sha256                                              
        filename                 KEY
        ------------------------------------------------------------
        -----------------------------------------
        d7d9c1dd5cfb8687a641daab19254f24e6ab4f2677f263acd21742e42ff02a50  
        6202_ifix.160830.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 AIX Security at security-alert@austin.ibm.com and
            describe the discrepancy.
            
            Published advisory OpenSSL signature file location:

       
http://aix.software.ibm.com/aix/efixes/security/openssh_advisory9.asc.sig
       
https://aix.software.ibm.com/aix/efixes/security/openssh_advisory9.asc.sig
        ftp://aix.software.ibm.com/aix/efixes/security/openssh_advisory9.asc.sig
      

        openssl dgst -sha1 -verify 
   
     -signature
            
    
     .sig 
     
      

        openssl dgst -sha1 -verify 
      
        -signature
            
       
        .sig 
        
         
  

        
            
    B. FIX AND INTERIM FIX INSTALLATION

        After applying fix, IBM recommends that you regenerate your SSH keys as
        a precaution. 

        IMPORTANT: 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:

    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
 
    Comments regarding the content of this announcement can be
    directed to:

        security-alert@austin.ibm.com

    To obtain the OpenSSL public key that can be used to verify the
    signed advisories and ifixes:

        Download the key from our web page:

    http://www.ibm.com/systems/resources/systems_p_os_aix_security_pubkey.txt

    To obtain the PGP public key that can be used to communicate
    securely with the AIX Security Team via security-alert@austin.ibm.com you
    can either:

        A. Download the key from our web page:

http://www.ibm.com/systems/resources/systems_p_os_aix_security_pgppubkey.txt

        B. Download the key from a PGP Public Key Server. The key ID is:

            0x28BFAA12

    Please contact your local IBM AIX support center for any
    assistance.


REFERENCES:

    Note: Keywords labeled as KEY in this document are used for parsing
purposes.

    eServer is a trademark of International Business Machines
    Corporation.  IBM, AIX and pSeries are registered trademarks of
    International Business Machines Corporation.  All other trademarks
    are property of their respective holders.

    Complete CVSS v3 Guide:  http://www.first.org/cvss/user-guide
    On-line Calculator v3:
        http://www.first.org/cvss/calculator/3.0

    X-Force Vulnerability Database:
https://exchange.xforce.ibmcloud.com/vulnerabilities/114628
    X-Force Vulnerability Database:
https://exchange.xforce.ibmcloud.com/vulnerabilities/115128
    X-Force Vulnerability Database:
https://exchange.xforce.ibmcloud.com/vulnerabilities/115911
    CVE-2015-8325 : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2015-8325
    CVE-2016-6210 : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-6210
    CVE-2016-6515 : http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2016-6515
    

ACKNOWLEDGEMENTS:

    None
    
    
CHANGE HISTORY:

    First Issued: Thu Sep  8 14:36:37 CDT 2016


===============================================================================

    *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 Flash.

    Note: 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.

        

       

      

     

    

   
Doc number: 5014 Published date: 20160923

Document information

More support for: Unclassified - SW Type

Operating system(s): aix tools

Reference #: SSRVPOAIX71SECURITY1
60923-1047

Modified date: 23 September 2016