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2017-04 Security Bulletin: Junos: Multiple vulnerabilities in NTP [VU#633847]



Article ID: JSA10776 SECURITY_ADVISORIES Last Updated: 18 May 2017Version: 6.0
Product Affected:
These issues can affect any product or platform running Junos OS with NTP services enabled
Problem: and FreeBSD have published security advisories for vulnerabilities resolved in ntpd (NTP daemon). The following is a summary of the vulnerabilities that may impact Junos OS:
CVE CVSS v2 base score Summary
CVE-2016-9311 7.1 (AV:N/AC:M/Au:N/C:N/I:N/A:C) ntpd in NTP before 4.2.8p9, when the trap service is enabled, allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via a crafted packet.
CVE-2016-9310 6.4 (AV:N/AC:L/Au:N/C:P/I:N/A:P) The control mode (mode 6) functionality in ntpd in NTP before 4.2.8p9 allows remote attackers to set or unset traps via a crafted control mode packet.
CVE-2015-7973 5.8 (AV:N/AC:M/Au:N/C:N/I:P/A:P) NTP before 4.2.8p6 and 4.3.x before 4.3.90, when configured in broadcast mode, allows man-in-the-middle attackers to conduct replay attacks by sniffing the network.
CVE-2015-7979 5.0 (AV:N/AC:L/Au:N/C:N/I:N/A:P) NTP before 4.2.8p6 and 4.3.x before 4.3.90 allows remote attackers to cause a denial of service (client-server association tear down) by sending broadcast packets with invalid authentication to a broadcast client.
CVE-2016-7431 5.0 (AV:N/AC:L/Au:N/C:N/I:P/A:N) NTP before 4.2.8p9 allows remote attackers to bypass the origin timestamp protection mechanism via an origin timestamp of zero. NOTE: this vulnerability exists because of a CVE-2015-8138 regression.
CVE-2015-8158 4.3 (AV:N/AC:M/Au:N/C:N/I:N/A:P) The getresponse function in ntpq in NTP versions before 4.2.8p9 and 4.3.x before 4.3.90 allows remote attackers to cause a denial of service (infinite loop) via crafted packets with incorrect values.
CVE-2016-7429 4.3 (AV:N/AC:M/Au:N/C:N/I:N/A:P) NTP before 4.2.8p9 changes the peer structure to the interface it receives the response from a source, which allows remote attackers to cause a denial of service (prevent communication with a source) by sending a response for a source to an interface the source does not use.
CVE-2016-7427 3.3 (AV:A/AC:L/Au:N/C:N/I:N/A:P) The broadcast mode replay prevention functionality in ntpd in NTP before 4.2.8p9 allows remote attackers to cause a denial of service (reject broadcast mode packets) via a crafted broadcast mode packet.

Server-side vulnerabilities are only exploitable on systems where NTP server is enabled within the [edit system ntp] hierarchy level.

These issues can affect systems with IPv4 or IPv6 enabled.
The following software releases have been updated to resolve these specific issues: Junos OS 12.1X46-D66, 12.3X48-D45, 14.1R8-S3, 14.1R9, 14.1X53-D44, 14.2R4-S8, 14.2R7-S6, 14.2R8, 15.1F2-S16, 15.1F5-S7, 15.1F6-S5, 15.1F7, 15.1R4-S7, 15.1R5-S2, 15.1R6, 15.1X49-D80, 15.1X53-D231, 15.1X53-D64, 15.1X53-D70, 16.1R3-S3, 16.1R4-S1, 16.1R5, 16.2R1-S3, 16.2R2, 17.1R1, 17.2R1, and all subsequent releases.

These issues are being tracked as PRs 1234119 and 1159544, and are visible on the Customer Support website.

KB16765 - "In which releases are vulnerabilities  fixed?" describes which release vulnerabilities are fixed as per our End of Engineering and End of Life support policies.
Standard security best current practices (control plane firewall filters, edge filtering, access lists, etc.) will protect against any remote malicious attacks against NTP. Customers who have already applied the workaround described in JSA10613 are already protected against any remote exploitation of these vulnerabilities.  Refer to the Workaround section of JSA10613 for specific applicable IPv4 mitigation techniques.

The firewall filters in the Workaround section of JSA10613 can also be updated or duplicated to protect IPv6 port 123/udp using 'next-header udp' and 'port ntp'.
How to obtain fixed software:
Security vulnerabilities in Junos are fixed in the next available Maintenance Release of each supported Junos version. In some cases, a Maintenance Release is not planned to be available in an appropriate time-frame. For these cases, Service Releases are made available in order to be more timely. Security Advisory and Security Notices will indicate which Maintenance and Service  Releases contain fixes for the issues described. Upon request to JTAC, customers will be provided download instructions for a Service Release. Although Juniper does not provide formal Release Note documentation for a Service Release, a list of "PRs fixed" can be provided on request.
Modification History:
2017-04-12: Initial publication
2017-04-25: Additional fixed releases
2017-05-09: Explicitly stated that both IPv4 and IPv6 are affected
2017-05-18: Additional fixed releases

CVSS Score:
6.5 (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:L)
Severity Level:
Severity Assessment:
Information for how Juniper Networks uses CVSS can be found at KB 16446 "Common Vulnerability Scoring System (CVSS) and Juniper's Security Advisories."

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