BSA-2017-383

Brocade Security Advisory ID

BSA-2017-383

Initial Publication Date

08/25/2017

Last Updated

10/13/2017

Revision

2.0: Interim

Risk Impact

Medium

Workaround

N/A

Component

OpenSSL

Affected CVE

CVE-2016-7056

CVSS Score

5.5

Summary

The signing function in crypto/ecdsa/ecdsa_ossl.c in certain OpenSSL versions and forks is vulnerable to timing attacks when signing with the standardized elliptic curve P-256 despite featuring constant-time curve operations and modular inversion. A software defect omits setting the BN_FLG_CONSTTIME flag for nonces, failing to take a secure code path in the BN_mod_inverse method and therefore resulting in a cache-timing attack vulnerability. A malicious user with local access can recover ECDSA P-256 private keys.

Affected Products

Brocade is investigating its product lines to determine which products may be affected by this vulnerability and the impact on each affected product.

Products Confirmed Not Vulnerable

Brocade Fabric OS, Brocade ServerIron ADX, and Brocade Workflow Composer is confirmed not affected by this vulnerability.

Workaround

There are no workarounds that address this vulnerability.


Revision History

Version Change Date
1.0 Initial Publication August 25, 2017
2.0 Updated to address ADX & WC October 13, 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.