Preview Tool

Cisco Bug: CSCum76937 - CUCM Distributed denial-of-service vulnerability on NTP server

Last Modified

Nov 27, 2020

Products (1)

  • Cisco Unified Communications Manager (CallManager)

Known Affected Releases

8.5(1) 8.6(2) 9.1(2)

Description (partial)

Cisco Unified Communications Manager (CallManager) includes a version of ntpd that is affected by the vulnerability identified by the following Common Vulnerability and Exposures (CVE) ID:


This bug was opened to address the potential impact on this product.

Device configured to use/broadcast NTP.

Related Community Discussions

<key>CSCum76937</key> - CUCM Distributed denial-of-service vulnerability on NTP server
I'd request that the built-in iptables on the CUCM, which we users can't adjust at all, could be autoadjusted by the CUCM itself to remove this DDOS vector, namely by restricting NTP to/from the CUCM only to these hosts:    the NTP server(s) it talks with, as configured in 'System&gt;Phone NTP Reference'    the device(s) subscribed to it, who get their time from it. why can that not be done?
Latest activity: Mar 10, 2014
Bug details contain sensitive information and therefore require a account to be viewed.

Bug Details Include

  • Full Description (including symptoms, conditions and workarounds)
  • Status
  • Severity
  • Known Fixed Releases
  • Related Community Discussions
  • Number of Related Support Cases
Bug information is viewable for customers and partners who have a service contract. Registered users can view up to 200 bugs per month without a service contract.