IBM SECURITY ADVISORY First Issued: Mon Oct 26 15:14:11 CDT 2020 The most recent version of this document is available here: http://aix.software.ibm.com/aix/efixes/security/ntp_advisory13.asc https://aix.software.ibm.com/aix/efixes/security/ntp_advisory13.asc ftp://aix.software.ibm.com/aix/efixes/security/ntp_advisory13.asc Security Bulletin: Vulnerabilities in NTPv4 affect AIX (CVE-2020-11868, CVE-2020-13817, and CVE-2020-15025) =============================================================================== SUMMARY: There are vulnerabilities in NTPv4 that affect AIX. =============================================================================== VULNERABILITY DETAILS: CVEID: CVE-2020-11868 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-11868 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-11868 DESCRIPTION: ntpd in ntp before 4.2.8p14 and 4.3.x before 4.3.100 allows an off-path attacker to block unauthenticated synchronization via a server mode packet with a spoofed source IP address, because transmissions are rescheduled even when a packet lacks a valid origin timestamp. CVSS Base Score: 5.9 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/180011 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H) CVEID: CVE-2020-13817 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-13817 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-13817 DESCRIPTION: NTP is vulnerable to a denial of service, caused by an issue when relying on unauthenticated IPv4 time sources in ntpd. By predicting transmit timestamps for use in spoofed packets, a remote attacker could exploit this vulnerability to cause the daemon to crash or system time change. CVSS Base Score: 7.4 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/183494 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H) CVEID: CVE-2020-15025 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-15025 https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2020-15025 DESCRIPTION: ntpd in ntp 4.2.8 before 4.2.8p15 and 4.3.x before 4.3.101 allows remote attackers to cause a denial of service (memory consumption) by sending packets, because memory is not freed in situations where a CMAC key is used and associated with a CMAC algorithm in the ntp.keys file. CVSS Base Score: 4.4 CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/184004 for the current score CVSS Environmental Score*: Undefined CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:H/UI:N/S:U/C:N/I:N/A:H) AFFECTED PRODUCTS AND VERSIONS: AIX 7.1, 7.2 VIOS 3.1 The vulnerabilities in the following filesets are being addressed: key_fileset = aix Fileset Lower Level Upper Level KEY PRODUCT(S) --------------------------------------------------------------------- ntp.rte 7.4.2.8100 7.4.2.8130 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 bos.net.tcp.client REMEDIATION: A. APARS IBM has assigned the following APARs to this problem: AIX Level APAR Availability SP KEY PRODUCT(S) ------------------------------------------------------------ 7.1.5 IJ26684 ** N/A key_w_apar NTPv4 7.2.2 IJ26684 ** N/A key_w_apar NTPv4 7.2.3 IJ26684 ** N/A key_w_apar NTPv4 7.2.4 IJ26684 ** N/A key_w_apar NTPv4 VIOS Level APAR Availability SP KEY PRODUCT(S) ---------------------------------------------------------------- 2.2.6 IJ26684 ** N/A key_w_apar NTPv4 3.1.0 IJ26684 ** N/A key_w_apar NTPv4 3.1.1 IJ26684 ** N/A key_w_apar NTPv4 Subscribe to the APARs here: https://www.ibm.com/support/pages/apar/IJ26684 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 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_fix13.tar http://aix.software.ibm.com/aix/efixes/security/ntp_fix13.tar https://aix.software.ibm.com/aix/efixes/security/ntp_fix13.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 PRODUCT(S) ---------------------------------------------------------- 7.1.x IJ26684s9a.200806.epkg.Z key_w_fix NTPv4 7.2.x IJ26684s9a.200806.epkg.Z key_w_fix NTPv4 VIOS Level Interim Fix (*.Z) KEY PRODUCT(S) ----------------------------------------------------------- 3.1.x IJ26684s9a.200806.epkg.Z key_w_fix NTPv4 To extract the fixes from the tar file: tar xvf ntp_fix13.tar cd ntp_fix13 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 ----------------------------------------------------------------------------------------------------- 4a7e37946fae27da239e575b2a917ca5a82bbc9d31be1610b27b394d26ce9523 IJ26684s9a.200806.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_advisory13.asc.sig https://aix.software.ibm.com/aix/efixes/security/ntp_advisory13.asc.sig ftp://aix.software.ibm.com/aix/efixes/security/ntp_advisory13.asc.sig C. 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-2020-11868, CVE-2020-13817, and CVE-2020-15025): https://www.ibm.com/support/pages/node/6353453 ACKNOWLEDGEMENTS: None. CHANGE HISTORY: First Issued: Mon Oct 26 15:14:11 CDT 2020 =============================================================================== *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.