Vulnerabilities in OpenSSL impact AIX

IBM SECURITY ADVISORY

First Issued: Mon Jan 18 10:47:32 CST 2016

The most recent version of this document is available here:

http://aix.software.ibm.com/aix/efixes/security/openssl_advisory15.asc
https://aix.software.ibm.com/aix/efixes/security/openssl_advisory15.asc
ftp://aix.software.ibm.com/aix/efixes/security/openssl_advisory15.asc

Security Bulletin: Vulnerabilities in OpenSSL affect AIX
CVE-2015-3194 CVE-2015-3195 CVE-2015-3196

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

SUMMARY:

There are multiple vulnerabilities in OpenSSL that impact AIX.

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

VULNERABILITY DETAILS:

CVEID: CVE-2015-3194
DESCRIPTION: OpenSSL allows remote attackers to cause a denial of service 
    (NULL pointer dereference and application crash) via an RSA PSS ASN.1 
    signature that lacks a mask generation function parameter.
CVSS Base Score: 5.3 
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/108503 for the
    current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:N/I:N/A:P)

CVEID: CVE-2015-3195
DESCRIPTION: The ASN1_TFLG_COMBINE implementation in OpenSSL mishandles 
    errors caused by malformed X509_ATTRIBUTE data, which allows remote 
    attackers to obtain sensitive information from process memory by 
    triggering a decoding failure in a PKCS#7 or CMS application.
CVSS Base Score: 5.3 
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/108504 for the
    current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:L/Au:N/C:P/I:N/A:N)

CVEID: CVE-2015-3196
DESCRIPTION: OpenSSL when used for a multi-threaded client, writes the 
    PSK identity hint to an incorrect data structure, which allows remote
    servers to cause a denial of service (race condition and double free)
    via a crafted ServerKeyExchange message.
CVSS Base Score: 3.7 
CVSS Temporal Score: See
    https://exchange.xforce.ibmcloud.com/vulnerabilities/108505 for the
    current score
CVSS Environmental Score*: Undefined
CVSS Vector: (AV:N/AC:M/Au:N/C:N/I:N/A:P)


AFFECTED PRODUCTS AND VERSIONS:

    AIX 5.3, 6.1, 7.1, 7.2
    VIOS 2.2.x

    The following fileset levels are vulnerable:
    
    key_fileset = osrcaix

    A. CVE-2015-3194, CVE-2015-3196

        Fileset          Lower Level  Upper Level KEY 
        --------------------------------------------------
        openssl.base     1.0.1.500    1.0.1.515   key_w_fs

    B. CVE-2015-3195

        Fileset          Lower Level  Upper Level KEY  
        --------------------------------------------------
        openssl.base     1.0.1.500     1.0.1.515  key_w_fs
        openssl.base     0.9.8.401     0.9.8.2506 key_w_fs
        openssl.base    12.9.8.1100   12.9.8.2506 key_w_fs

    Note, 0.9.8.401 and 12.9.8.1100 are the Lowest OpenSSL version
    available in aix web download site. Even OpenSSL versions below 
    this are impacted

    Note:  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 openssl.base

REMEDIATION:

    A. FIXES

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

        ftp://aix.software.ibm.com/aix/efixes/security/openssl_fix15.tar
        http://aix.software.ibm.com/aix/efixes/security/openssl_fix15.tar
        https://aix.software.ibm.com/aix/efixes/security/openssl_fix15.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.
        
        Note that the tar file contains Interim fixes that are based on 
        OpenSSL version.

        AIX Level           Interim Fix (*.Z)        Fileset Name(prereq for installation) KEY
        --------------------------------------------------------------------------------------------
        5.3, 6.1, 7.1, 7.2  101_ifix.151218.epkg.Z   openssl.base(1.0.1.515 version)       key_w_fix
        5.3, 6.1, 7.1, 7.2  098_ifix.151218.epkg.Z   openssl.base(0.9.8.2506 version)      key_w_fix
        5.3, 6.1, 7.1, 7.2  1298_ifix.151218.epkg.Z  openssl.base(12.9.8.2506 version)     key_w_fix

        VIOS Level     Interim Fix (*.Z)             Fileset Name(prereq for installation) KEY
        --------------------------------------------------------------------------------------------
        2.2.*          101_ifix.151218.epkg.Z        openssl.base(1.0.1.515 version)       key_w_fix
        2.2.*          098_ifix.151218.epkg.Z        openssl.base(0.9.8.2506 version)      key_w_fix
        2.2.*          1298_ifix.151218.epkg.Z       openssl.base(12.9.8.2506 version)     key_w_fix


        To extract the fixes from the tar file:

        tar xvf openssl_fix15.tar
        cd openssl_fix15

        Verify you have retrieved the fixes intact:

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

        openssl dgst -sha256                                              filename                KEY
        ----------------------------------------------------------------------------------------------------
        b65b7ce60380ac988767dd4319002ceb82c18d4786f8d6de014b58028f8bf847  101_ifix.151218.epkg.Z  key_w_csum
        0fb34df46591a4c4ff9c468e75da2e9c0a7541f3a0cda325c2fe28df1baa0571  098_ifix.151218.epkg.Z  key_w_csum
        d820d31b37fb9ffb51abdd504066f6a752fb0b8d83d305a6b7f4267161d5cf61  1298_ifix.151218.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
        [email protected] 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/openssl_advisory15.asc.sig
        https://aix.software.ibm.com/aix/efixes/security/openssl_advisory15.asc.sig
        ftp://aix.software.ibm.com/aix/efixes/security/openssl_advisory15.asc.sig 

    B. FIX AND INTERIM FIX INSTALLATION

        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:

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

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

    [email protected]

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 [email protected] 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:

Complete CVSS Guide:  http://www.first.org/cvss/cvss-guide.html
On-line Calculator V2:
    http://nvd.nist.gov/cvss.cfm?calculator&adv&version=2

ACKNOWLEDGEMENTS:

None 

CHANGE HISTORY:

First Issued: Mon Jan 18 10:47:32 CST 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 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.