IBM SECURITY ADVISORY First Issued: Wed Jul 3 09:33:57 CDT 2013 | Updated: Mon Oct 14 20:17:56 CDT 2013 | Update: Fixed vulnerable fileset levels | Update: More workarounds and CVSS Vector | Update: Includes VIOS in the vulnerability summary | Updated: Thu Dec 12 12:55:11 CST 2013 | Update: 1. Added KEYs for parsing purposes | 2. Moved to OpenSSL signature http://aix.software.ibm.com/aix/efixes/security/tftp_advisory.asc ftp://aix.software.ibm.com/aix/efixes/security/tftp_advisory.asc =============================================================================== VULNERABILITY SUMMARY VULNERABILITY: tftp Security Vulnerability PLATFORMS: AIX 6.1 and 7.1 releases | VIOS 2.X SOLUTION: Apply the fix as described below THREAT: See below CVE Number: CVE-2013-3005 CVSS=7.9 Reboot required? YES Workarounds? YES Protected by FPM? NO Protected by SED? NO =============================================================================== DETAILED INFORMATION I. DESCRIPTION A non-root user can read and overwrite files owned by others including root via tftp client. II. CVSS CVSS Base Score: 7.9 CVSS Temporal Score: See http://xforce.iss.net/xforce/xfdb/85366 for the current score CVSS Environmental Score*: Undefined | CVSS String: (AV:N/AC:M/Au:S/C:C/I:C/A:N) III. PLATFORM VULNERABILITY ASSESSMENT Note: To use the following commands on VIOS you must first execute: oem_setup_env To determine if your system is vulnerable, execute the following command: lslpp -L bos.net.tcp.client The following fileset levels are vulnerable: AIX Fileset Lower Level Upper Level KEY ---------------------------------------------------------- bos.net.tcp.client 6.1.6.0 6.1.6.22 key_w_fs bos.net.tcp.client 6.1.7.0 6.1.7.18 key_w_fs bos.net.tcp.client 6.1.8.0 6.1.8.15 key_w_fs bos.net.tcp.client 7.1.0.0 7.1.0.23 key_w_fs bos.net.tcp.client 7.1.1.0 7.1.1.18 key_w_fs | bos.net.tcp.client 7.1.2.0 7.1.2.15 key_w_fs IV. SOLUTIONS A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR number Availability KEY ----------------------------------------------------------------- 6.1.6 IV40221 08/16/13 SP12 key_w_apar 6.1.7 IV42932 08/16/13 SP8 key_w_apar 6.1.8 IV42933 08/16/13 SP3 key_w_apar 7.1.0 IV42934 08/16/13 SP10 key_w_apar 7.1.1 IV42700 08/16/13 SP8 key_w_apar 7.1.2 IV42935 08/16/13 SP3 key_w_apar Subscribe to the APARs here: http://www.ibm.com/support/docview.wss?uid=isg1IV40221 http://www.ibm.com/support/docview.wss?uid=isg1IV42932 http://www.ibm.com/support/docview.wss?uid=isg1IV42933 http://www.ibm.com/support/docview.wss?uid=isg1IV42934 http://www.ibm.com/support/docview.wss?uid=isg1IV42700 http://www.ibm.com/support/docview.wss?uid=isg1IV42935 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 Fixes are available. The fixes can be downloaded via ftp from: ftp://aix.software.ibm.com/aix/efixes/security/tftp_fix.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 ------------------------------------------------------------------ 6.1.6.11 IV40221s11.130617.epkg.Z key_w_fix 6.1.7.7 IV42932s7a.130617.epkg.Z key_w_fix 6.1.8.2 IV42933s2a.130617.epkg.Z key_w_fix 7.1.0.9 IV42934s9a.130617.epkg.Z key_w_fix 7.1.1.7 IV42700s7a.130617.epkg.Z key_w_fix 7.1.2.2 IV42935s2a.130617.epkg.Z key_w_fix VIOS Level Interim Fix (*.Z) ------------------------------------------------------------------- 2.2.2.2-FP-26 SP-02 IV42933s2a.130617.epkg.Z To extract the fixes from the tar file: tar xvf tftp_fix.tar cd tftp_fix Verify you have retrieved the fixes intact: The checksums below were generated using the "csum -h SHA1" (sha1sum) command is the followng: csum -h SHA1 (sha1sum) filename ------------------------------------------------------------------ 3a9b2000311c72c12fa8b870e6e6ae559dafe77b IV40221s11.130617.epkg.Z eda458143757610c4674640498b60496e8e4ee7a IV42932s7a.130617.epkg.Z 2dcdc2bfbecb88c6128cef0c5c738b4d15278283 IV42933s2a.130617.epkg.Z dfa9d5c25fd1b3a047b0531f1899f3ecc72e8653 IV42934s9a.130617.epkg.Z c640ec0f67a1111d330dd1686a3b905bbb3b04df IV42700s7a.130617.epkg.Z 36985ee2f2d0f6d54d5184c8bfd7bef95432baf9 IV42935s2a.130617.epkg.Z To verify the sum, use the text of this advisory as input to sha1sum. For example: csum -h SHA1 -i Advisory.asc sha1sum -c Advisory.asc 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. openssl dgst -sha1 -verify AIX_PSIRT_pub.asc -signature file.asc.sig file.asc C. 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. V. WORKAROUNDS | 1) Disabling RBAC on the nodes will prevent this vulnerability. Steps below: 1. lsattr -E -l sys0 -a enhanced_RBAC 2. chdev -l sys0 -a enhanced_RBAC=false 3. reboot 4. lsattr -E -l sys0 -a enhanced_RBAC | 2) Enabling PowerSC with PCI.xml profile will disable tftpd and does | not require a reboot. | 3) Running aixpert with high-level security options (aixpert -l high) | 4) Running aixpert with medium-level security options (aixpert -l medium) VI. OBTAINING FIXES AIX security fixes can be downloaded from: ftp://aix.software.ibm.com/aix/efixes/security AIX fixes can be downloaded from: http://www.ibm.com/eserver/support/fixes/fixcentral/main/pseries/aix NOTE: Affected customers are urged to upgrade to the latest applicable Technology Level and Service Pack. VII. CONTACT INFORMATION If you would like to receive AIX Security Advisories via email, 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 request the PGP public key that can be used to communicate securely with the AIX Security Team you can either: A. Send an email with "get key" in the subject line to: security-alert@austin.ibm.com 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. 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. VIII. REFERENCES: Note: Keywords labeled as KEY in this document are used for parsing purposes. 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 X-Force Vulnerability Database: http://xforce.iss.net/xforce/xfdb/85366 CVE-2013-3005: http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2013-3005 *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.