Cisco Security Advisory
Click Icon to Copy Verbose Score
AV:N/AC:L/Au:N/C:P/I:N/A:N/E:F/RL:OF/RC:C
-
A vulnerability in the implementation of the ntp access-group command in Cisco IOS Software and Cisco IOS XE Software could allow an unauthenticated, remote attacker to bypass the configured Network Time Protocol (NTP) access group and query the affected NTP-configured server for the time.
The vulnerability is due to improper implementation of the ntp access-group command in certain Cisco IOS Software and Cisco IOS XE Software versions. An attacker could exploit this vulnerability by sending NTP query packets to an affected NTP server configured to deny all requests. An exploit could allow the attacker to bypass the configured NTP access group and query the affected NTP-configured server for the time.
Cisco has confirmed the vulnerability in a security notice and released software updates.
To exploit this vulnerability, the targeted NTP server must be configured to deny all requests. In addition, the attacker must send NTP query packets to the targeted system. Depending on where the targeted system is in the environment, an attacker may need access to trusted, internal networks behind a firewall to send NTP query packets to the system. This requirement may decrease the likelihood of a successful exploit.
-
Customers are advised to consult Cisco bug ID CSCuj66318 for a complete list of affected product versions.
Vulnerable Products
At the time this alert was first published, Cisco IOS Software Releases 15.4(1)T and prior and Cisco IOS XE Software Releases 3.11S(.2) and prior were vulnerable. Later releases may also be vulnerable.Products Confirmed Not Vulnerable
No other Cisco products are currently known to be affected by these vulnerabilities.
-
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
It is critical to prevent unauthorized direct communication to network devices. Restrict network traffic destined for the network infrastructure to protect against reconnaissance and denial of service attacks. For configuration details, see Protecting Your Core: Infrastructure Protection Access Control Lists.
Administrators are advised to monitor affected systems.
-
Cisco customers with active contracts should contact their Cisco support team for assistance in upgrading to a software version that includes fixes for this vulnerability. Cisco customers without contracts may contact the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at tac@cisco.com for assistance.
-
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerability that is described in this advisory.
-
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
-
Show LessVersion Description Section Status Date 1.0 Initial Release NA Final 2014-Jul-09
-
THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.
A stand-alone copy or paraphrase of the text of this document that omits the distribution URL is an uncontrolled copy, and may lack important information or contain factual errors. The information in this document is intended for end-users of Cisco products.