IBM SECURITY ADVISORY First Issued: Fri Dec 14 12:20:13 CST 2018 The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/security/ntp_advisory11.asc https://aix.software.ibm.com/aix/efixes/security/ntp_advisory11.asc ftp://aix.software.ibm.com/aix/efixes/security/ntp_advisory11.asc Security Bulletin: Vulnerabilities in NTPv4 affect AIX (CVE-2018-12327, CVE-2018-7170) =============================================================================== SUMMARY: There are vulnerabilities in NTPv4 that affect AIX. =============================================================================== VULNERABILITY DETAILS: NTPv4 is vulnerable to: CVEID: CVE-2018-12327 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12327 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-12327 DESCRIPTION: NTP is vulnerable to a stack-based buffer overflow, caused by improper bounds checking by ntpq and ntpdc. By sending an overly long string argument, a local attacker could overflow a buffer and execute arbitrary code on the system with elevated privileges or cause the application to crash. CVSS Base Score: 5.9 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/145120 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L) CVEID: CVE-2018-7170 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-7170 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2018-7170 DESCRIPTION: NTP could allow a remote authenticated attacker to bypass security restrictions, caused by a Sybil attack. By creating many ephemeral associations, an attacker could exploit this vulnerability to win the clock selection of ntpd and modify a victim's clock. CVSS Base Score: 3.1 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/139786 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:L/A:N) AFFECTED PRODUCTS AND VERSIONS: AIX 6.1, 7.1, 7.2 VIOS 2.2.x The vulnerabilities in the following filesets are being addressed: key_fileset = aix For NTPv4: Fileset Lower Level Upper Level KEY PRODUCT(S) --------------------------------------------------------------------- ntp.rte 7.4.2.8100 7.4.2.8110 key_w_fs NTPv4 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 ntp.rte REMEDIATION: FIXES AIX and VIOS fixes are available. The AIX/VIOS fixes can be downloaded via ftp or http from: ftp://aix.software.ibm.com/aix/efixes/security/ntp_fix11.tar http://aix.software.ibm.com/aix/efixes/security/ntp_fix11.tar https://aix.software.ibm.com/aix/efixes/security/ntp_fix11.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 NTPv4: AIX Level Interim Fix (*.Z) KEY PRODUCT(S) ---------------------------------------------------------- 6.1.x IJ10280s3b.181206.epkg.Z key_w_fix NTPv4 7.1.x IJ10280s3b.181206.epkg.Z key_w_fix NTPv4 7.2.x IJ10280s3b.181206.epkg.Z key_w_fix NTPv4 VIOS Level Interim Fix (*.Z) KEY PRODUCT(S) ----------------------------------------------------------- 2.2.x IJ10280s3b.181206.epkg.Z key_w_fix NTPv4 To extract the fixes from the tar file: tar xvf ntp_fix11.tar cd ntp_fix11 Verify you have retrieved the fixes intact: The checksums below were generated using the "openssl dgst -sha256 file" command as the following: openssl dgst -sha256 filename KEY ----------------------------------------------------------------------------------------------------- 000891c62f5e59c34909399d0ef4c74c72048a4fc1e7e50b66dedaa4fcf0ee87 IJ10280s3b.181206.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/ntp_advisory11.asc.sig https://aix.software.ibm.com/aix/efixes/security/ntp_advisory11.asc.sig ftp://aix.software.ibm.com/aix/efixes/security/ntp_advisory11.asc.sig 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. The fix will not take affect until any running xntpd servers have been stopped and restarted with the following commands: stopsrc -s xntpd startsrc -s xntpd 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. After installation the ntp daemon must be restarted: stopsrc -s xntpd startsrc -s xntpd 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 Contact IBM Support for questions related to this announcement: 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 NTPv4 affect AIX (CVE-2018-12327, CVE-2018-7170) https://www-01.ibm.com/support/docview.wss?uid=ibm10744497 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Fri Dec 14 12:20:13 CST 2018 =============================================================================== *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.