Brocade Security Advisory

Brocade Security Advisory ID:

BSA-2017-337

 

Risk Impact:

High

Initial Publication Date:

June 23, 2017

 

Workaround:

N/A

Last Updated:

September 8, 2017

 

Component:

OpenVPN

Revision:

2.0: Interim

 

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.