r1 - 2016-11-21 - 14:08:45 - HarlanStennYou are here: NTP >  Main Web > SecurityNotice > NtpBug3113
NTP users are strongly urged to take immediate action to ensure that their NTP daemons are not susceptible to being used in distributed denial-of-service (DDoS) attacks. Please also take this opportunity to defeat denial-of-service attacks by implementing Ingress and Egress filtering through BCP38.

ntp-4.2.8p9 was released on 21 November 2016. It addresses 1 high- (Windows only), 2 medum-, 2 medum-/low-, and 5 low-severity security issues, 28 bugfixes, and contains other improvements over 4.2.8p8.

Please see the NTP Security Notice for vulnerability and mitigation details.

Are you using Autokey in production? If so, please contact Harlan - he's got some questions for you.

NTP Bug 3113

Broadcast Mode Poll Interval Enforcement DoS

  • Date Resolved: 21 Nov 2016
  • References: Sec 3113 / CVE-2016-7428 / VU#633847
  • Affects: ntp-4.2.8p6, up to but not including ntp-4.2.8p9, and ntp-4.3.90 up to, but not including ntp-4.3.94.
  • CVSS2: LOW 3.3 (AV:A/AC:L/Au:N/C:N/I:N/A:P)
  • CVSS3: MED 4.3 CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
  • Summary: The broadcast mode of NTP is expected to only be used in a trusted network. If the broadcast network is accessible to an attacker, a potentially exploitable denial of service vulnerability in ntpd's broadcast mode poll interval enforcement functionality can be abused. To limit abuse, ntpd restricts the rate at which each broadcast association will process incoming packets. ntpd will reject broadcast mode packets that arrive before the poll interval specified in the preceding broadcast packet expires. An attacker with access to the NTP broadcast domain can send specially crafted broadcast mode NTP packets to the broadcast domain which, while being logged by ntpd, will cause ntpd to reject broadcast mode packets from legitimate NTP broadcast servers.
  • Mitigation:
  • Credit: This weakness was discovered by Matthew Van Gundy of Cisco.
Edit | WYSIWYG | Attach | Printable | Raw View | Backlinks: Web, All Webs | History: r1 | More topic actions
 
SSL security by CAcert
Get the CAcert Root Certificate
This site is powered by the TWiki collaboration platform
IPv6 Ready
Copyright & 1999-2017 by the contributing authors. All material on this collaboration platform is the property of the contributing authors. Ideas, requests, problems regarding the site? Send feedback