Security Bulletin: OpenSSL Vulnerability Affects IBM Sterling Connect:Express for UNIX (CVE-2019-1559)

Summary

A security vulnerability has been disclosed on 26th February 2019 by the OpenSSL Project. OpenSSl is used by IBM Sterling Connect:Express for UNIX. IBM Sterling Connect:Express for UNIX has addressed the applicable CVE.

Vulnerability Details

CVEID: CVE-2019-1559

**DESCRIPTION:**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). Fixed in OpenSSL 1.0.2r (Affected 1.0.2-1.0.2q).

CVSS Base Score: 5.8
CVSS Temporal Score: See <https://exchange.xforce.ibmcloud.com/vulnerabilities/157514&gt;
CVSS Environment Score*: Undefined
CVSS Vector: (CVSS: 3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N)

Affected Products and Versions

IBM Sterling Connect:Express for UNIX 1.5.0.15

All versions prior to and including 1.5.0.15 iFix 150-1510

Remediation/Fixes

Apply the OpenSSL 1.0.2r Updater for Connect:Express for Unix available on Fix Central.

Workarounds and Mitigations

None.