IBM SECURITY ADVISORY First Issued: Thu Jan 21 09:13:20 CST 2016 The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/security/ntp_advisory4.asc https://aix.software.ibm.com/aix/efixes/security/ntp_advisory4.asc ftp://aix.software.ibm.com/aix/efixes/security/ntp_advisory4.asc Security Bulletin: Vulnerabilities in NTP affect AIX CVE-2015-5219 CVE-2015-7691 CVE-2015-7692 CVE-2015-7701 CVE-2015-7702 CVE-2015-7850 CVE-2015-7853 CVE-2015-7855 =============================================================================== SUMMARY: There are multiple vulnerabilities in NTP that impact AIX. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2015-5219 DESCRIPTION: Network Time Protocol (NTP) is vulnerable to a denial of service, caused by an error in the sntp program. By sending specially crafted NTP packets, a remote attacker from within the local network could exploit this vulnerability to cause the application to enter into an infinite loop. CVSS Base Score: 4.3 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/107597 for more information. CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) CVEID: CVE-2015-7691 DESCRIPTION: Network Time Protocol (NTP) is vulnerable to a denial of service, caused by an error in ntp_crypto.c. An attacker could exploit this vulnerability using a packet containing an extension field with an invalid value for the length of its value field to cause ntpd to crash. CVSS Base Score: 5.3 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/107449 for more information. CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) CVEID: CVE-2015-7692 DESCRIPTION: Network Time Protocol (NTP) is vulnerable to a denial of service, caused by an error in ntp_crypto.c. An attacker could exploit this vulnerability using a packet containing an extension field with an invalid value for the length of its value field to cause ntpd to crash. CVSS Base Score: 5.3 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/107450 for more information. CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) CVEID: CVE-2015-7701 DESCRIPTION: Network Time Protocol (NTP) could allow a remote attacker to obtain sensitive information, caused by a memory leak in CRYPTO_ASSOC. An attacker could exploit this vulnerability to obtain sensitive information. CVSS Base Score: 5.3 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/107444 for more information. 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-2015-7702 DESCRIPTION: Network Time Protocol (NTP) is vulnerable to a denial of service, caused by an error in ntp_crypto.c. An attacker could exploit this vulnerability using a packet containing an extension field with an invalid value for the length of its value field to cause ntpd to crash. CVSS Base Score: 5.3 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/107451 for more information. CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) CVEID: CVE-2015-7850 DESCRIPTION: Network Time Protocol (NTP) is vulnerable to a denial of service, caused by an error in the remote configuration functionality. By sending a specially crafted configuration file, an attacker could exploit this vulnerability to cause the application to enter into an infinite loop. CVSS Base Score: 5.3 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/107441 for more information. CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) CVEID: CVE-2015-7853 DESCRIPTION: Network Time Protocol (NTP) is vulnerable to a buffer overflow, caused by improper bounds checking by the refclock of ntpd. By sending an overly long string, a remote attacker could overflow a buffer and execute arbitrary code on the system or cause the application to crash. CVSS Base Score: 7.3 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/107438 for more information. CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L) CVEID: CVE-2015-7855 DESCRIPTION: Network Time Protocol (NTP) is vulnerable to a denial of service, caused by ASSERT botch instead of returning FAIL on some invalid values by the decodenetnum() function. An attacker could exploit this vulnerability to cause a denial of service. CVSS Base Score: 5.3 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/107448 for more information. CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L) 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 = aix For NTPv3: Fileset Lower Level Upper Level KEY ----------------------------------------------------- bos.net.tcp.client 5.3.12.0 5.3.12.10 key_w_fs bos.net.tcp.client 6.1.9.0 6.1.9.101 key_w_fs bos.net.tcp.client 7.1.3.0 7.1.3.45 key_w_fs bos.net.tcp.client 7.1.4.0 7.1.4.0 key_w_fs bos.net.tcp.ntp 7.2.0.0 7.2.0.0 key_w_fs bos.net.tcp.ntpd 7.2.0.0 7.2.0.0 key_w_fs For NTPv4: Fileset Lower Level Upper Level KEY ----------------------------------------------------- ntp.rte 6.1.6.0 6.1.6.4 key_w_fs ntp.rte 7.1.0.0 7.1.0.4 key_w_fs 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 bos.net.tcp.client REMEDIATION: A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR Availability SP KEY ------------------------------------------------ 5.3.12 IV79946 N/A key_w_apar 6.1.9 IV79942 5/20/16 SP7 key_w_apar 7.1.3 IV79943 8/24/16 SP7 key_w_apar 7.1.4 IV79944 5/20/16 SP2 key_w_apar 7.2.0 IV79945 5/20/16 SP2 key_w_apar Subscribe to the APARs here: http://www.ibm.com/support/docview.wss?uid=isg1IV79942 http://www.ibm.com/support/docview.wss?uid=isg1IV79943 http://www.ibm.com/support/docview.wss?uid=isg1IV79944 http://www.ibm.com/support/docview.wss?uid=isg1IV79945 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 or http from: ftp://aix.software.ibm.com/aix/efixes/security/ntp_fix4.tar http://aix.software.ibm.com/aix/efixes/security/ntp_fix4.tar https://aix.software.ibm.com/aix/efixes/security/ntp_fix4.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. For NTPv3: AIX Level Interim Fix (*.Z) KEY ---------------------------------------------- 5.3.12.9 IV79946s9a.160119.epkg.Z key_w_fix 6.1.9.6 IV79942s6a.160119.epkg.Z key_w_fix 7.1.3.5 IV79943s5b.160119.epkg.Z key_w_fix 7.1.4.1 IV79944s1a.160119.epkg.Z key_w_fix 7.2.0.1 IV79945s1a.160119.epkg.Z key_w_fix VIOS Level Interim Fix (*.Z) KEY ----------------------------------------------- 2.2.4.0 IV79942s6a.160119.epkg.Z key_w_fix For NTPv4: AIX Level Interim Fix (*.Z) KEY ---------------------------------------------- 6.1.x IV79954m4a.160119.epkg.Z key_w_fix 7.1.x IV79955m4a.160119.epkg.Z key_w_fix 7.2.x IV79955m4a.160119.epkg.Z key_w_fix VIOS Level Interim Fix (*.Z) KEY ----------------------------------------------- 2.2.x IV79954m4a.160119.epkg.Z key_w_fix To extract the fixes from the tar file: tar xvf ntp_fix4.tar cd ntp_fix4 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 ----------------------------------------------------------------------------------------------------- 15f2849528a5ffddc55d59cc06f05f21898d8b30533bd7b785693903e341c790 IV79946s9a.160119.epkg.Z key_w_csum 55e95de0ef1d6ba9b262bd2138e52ea0d3434c9e3a44927e072f3c658b869e8f IV79942s6a.160119.epkg.Z key_w_csum f29b0fbf654f8bd12c2718320894d4bdea0fd11a6a8f621aec8d71625702d7a6 IV79943s5b.160119.epkg.Z key_w_csum ce1758fb35b9eb464c3633beef9daeb2e7ef9bc1ae8fb8f38a3029fdf27d04a4 IV79944s1a.160119.epkg.Z key_w_csum 190254a853d1adcda0d420ebc680b1dfacc48ca1de4a7070e55c8f0469cc233b IV79945s1a.160119.epkg.Z key_w_csum 7d9ba87d561eb6dc0a2d865676501b1c5e278f8c95ffccba27edbaae031f9e23 IV79954m4a.160119.epkg.Z key_w_csum 18974bfd95db93b82ceb04d57a54e76808cb8f4d37e7bc00a67406a551354e30 IV79955m4a.160119.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. openssl dgst -sha1 -verify -signature .sig openssl dgst -sha1 -verify -signature .sig Published advisory OpenSSL signature file location: http://aix.software.ibm.com/aix/efixes/security/ntp_advisory4.asc.sig https://aix.software.ibm.com/aix/efixes/security/ntp_advisory4.asc.sig ftp://aix.software.ibm.com/aix/efixes/security/ntp_advisory4.asc.sig 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. 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 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: Complete CVSS v3 Guide: http://www.first.org/cvss/user-guide On-line Calculator v3: http://www.first.org/cvss/calculator/3.0 ACKNOWLEDGEMENTS: None CHANGE HISTORY: First Issued: Thu Jan 21 09:13:20 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.