BSA-2017-337

Brocade Security Advisory ID

BSA-2017-337

Initial Publication Date

06/23/2017

Last Updated

09/08/2017

Revision

2.0: Interim

Risk Impact

High

Workaround

N/A

Component

OpenVPN

Affected CVE

CVE-2017-7478

CVSS Score

8.0

Summary

An authenticated client can do the 'three way handshake' (P_HARD_RESET, P_HARD_RESET, P_CONTROL), where the P_CONTROL packet is the first that is allowed to carry payload. If that payload is too big, the OpenVPN server process will stop running due to an ASSERT() exception. That is also the reason why servers using tls-auth/tls-crypt are protected against this attack - the P_CONTROL packet is only accepted if it contains the session ID we specified, with a valid HMAC (challenge-response). This affects OpenVPN 2.3.12 and newer. OpenVPN versions 2.3.15, 2.4.2 and later include these fixes.

Affected Products
Product Current Assessment
Brocade 5400 vRouter Impacted: Fixed in 6.7R14.
Brocade 5600 vRouter Impacted: Fixed in 17.2.0.
Products Confirmed Not Vulnerable

Brocade Fabric OS, Brocade FastIron OS, Brocade NetIron OS, Brocade Network OS, Brocade ServerIron ADX, Brocade Services Director, Brocade SLX-OS, and Brocade Virtual ADX, Brocade Virtual Traffic Manager, 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 June 23, 2017
2.0 Updated to address NOS September 8, 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.