Is this a client-side or server-side vulnerability?  Or does it matter?

Thanks,

ScottN

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Scott Neugroschl | XYPRO Technology Corporation
4100 Guardian Street | Suite 100 |Simi Valley, CA 93063 | Phone 805 
583-2874|Fax 805 583-0124 |




-----Original Message-----
From: openssl-users <openssl-users-boun...@openssl.org> On Behalf Of OpenSSL
Sent: Tuesday, February 26, 2019 6:59 AM
To: openssl-proj...@openssl.org; OpenSSL User Support ML 
<openssl-users@openssl.org>; OpenSSL Announce ML <openssl-annou...@openssl.org>
Subject: OpenSSL Security Advisory

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Hash: SHA512

OpenSSL Security Advisory [26 February 2019] 
============================================

0-byte record padding oracle (CVE-2019-1559) 
============================================

Severity: Moderate

If an application encounters a fatal protocol error and then calls
SSL_shutdown() twice (once to send a close_notify, and once to receive one) 
then OpenSSL can respond differently to the calling application if a 0 byte 
record is received with invalid padding compared to if a 0 byte record is 
received with an invalid MAC. If the application then behaves differently based 
on that in a way that is detectable to the remote peer, then this amounts to a 
padding oracle that could be used to decrypt data.

In order for this to be exploitable "non-stitched" ciphersuites must be in use.
Stitched ciphersuites are optimised implementations of certain commonly used 
ciphersuites. Also the application must call SSL_shutdown() twice even if a 
protocol error has occurred (applications should not do this but some do 
anyway).

This issue does not impact OpenSSL 1.1.1 or 1.1.0.

OpenSSL 1.0.2 users should upgrade to 1.0.2r.

This issue was discovered by Juraj Somorovsky, Robert Merget and Nimrod Aviram, 
with additional investigation by Steven Collison and Andrew Hourselt. It was 
reported to OpenSSL on 10th December 2018.

Note
====

OpenSSL 1.0.2 and 1.1.0 are currently only receiving security updates. Support 
for 1.0.2 will end on 31st December 2019. Support for 1.1.0 will end on 11th 
September 2019. Users of these versions should upgrade to OpenSSL 1.1.1.

References
==========

URL for this Security Advisory:
https://www.openssl.org/news/secadv/20190226.txt

Note: the online version of the advisory may be updated with additional details 
over time.

For details of OpenSSL severity classifications please see:
https://www.openssl.org/policies/secpolicy.html
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