Brocade Security Advisory

Brocade Security Advisory ID:

BSA-2017-225

 

Risk Impact:

Low

Initial Publication Date:

March 31, 2017

 

Workaround:

N/A

Last Updated:

 

 

Component:

ntp

Revision:

1.0: Interim

 

CVSS Score:

3.7

 

Affected CVE(s):

CVE-2016-7429

 

 

 

 

 

 

 

Summary

When ntpd receives a server response on a socket that corresponds to a different interface than was used for the request, the peer structure is updated to use the interface for new requests. If ntpd is running on a host with multiple interfaces in separate networks and the operating system doesn't check source address in received packets (e.g. rp_filter on Linux is set to 0), an attacker that knows the address of the source can send a packet with spoofed source address which will cause ntpd to select wrong interface for the source and prevent it from sending new requests until the list of interfaces is refreshed, which happens on routing changes or every 5 minutes by default. If the attack is repeated often enough (once per second), ntpd will not be able to synchronize with the source.

Affected Products

Product

Current Assessment

Brocade 5400 vRouter

Impacted: Fixed in 17.1.0.

Brocade 5600 vRouter

Impacted: Fixed in 6.7R13.

Products Confirmed Not Vulnerable

Brocade Fabric OS, Brocade FastIron OS, Brocade NetIron OS, Brocade Network Advisor, Brocade Network OS, Brocade SDN Controller, Brocade ServerIron ADX, Brocade SLX-OS, Brocade Virtual ADX, Brocade Virtual Traffic Manager: Software, and Brocade Virtual Web Application Firewall are confirmed not affected by this vulnerability.

Workaround

There are no workarounds that address this vulnerability.

Revision History

Version

Change

Date

1.0

Initial Publication

March 31, 2017

 

 

 

Disclaimer

THIS DOCUMENT IS PROVIDED ON AN AS-IS BASIS SOLELY FOR INFORMATIONAL PURPOSES AND DOES NOT IMPLY ANY KIND OF GUARANTY OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. YOUR USE OF THE INFORMATION CONTAINED HEREIN IS AT YOUR OWN RISK. ALL INFORMATION PROVIDED HEREIN IS BASED ON BROCADE'S CURRENT KNOWLEDGE AND UNDERSTANDING OF THE VULNERABILITY AND IMPACT TO BROCADE HARDWARE AND SOFTWARE PRODUCTS. BROCADE RESERVES THE RIGHT TO CHANGE OR UPDATE THIS DOCUMENT AT ANY TIME.