Security Bulletin: A Vulnerability in OpenSSH and Multiple Vulnerabilities in OpenSSL affect IBM GPFS V3.5 for Windows

Summary

OpenSSH could allow a remote authenticated attacker to execute arbitrary commands on the system, caused by improper validation of user-supplied X11 authentication credentials by the sshd server. OpenSSL vulnerabilities were disclosed on May 3, 2016 by the OpenSSL Project. OpenSSL is used by GPFS V3.5 for Windows. IBM GPFS V3.5 for Windows has addressed the applicable CVEs.

Vulnerability Details

CVEID: CVE-2016-3115**
DESCRIPTION:** OpenSSH could allow a remote authenticated attacker to execute arbitrary commands on the system, caused by improper validation of user-supplied X11 authentication credentials by the sshd server. By sending specially crafted X11 credential data, an attacker could exploit this vulnerability to inject xauth commands and execute arbitrary commands on the system with the privileges of the victim.
CVSS Base Score: 8.8
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/111431 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H)

CVEID: CVE-2016-2107 DESCRIPTION: OpenSSL could allow a remote attacker to obtain sensitive information, caused by an error when the connection uses an AES CBC cipher and the server support AES-NI. A remote user with the ability to conduct a man-in-the-middle attack could exploit this vulnerability via the POODLE (Padding Oracle On Downgraded Legacy Encryption) attack to decrypt traffic.
CVSS Base Score: 4.3
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/112854 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:L/I:N/A:N)

CVEID: CVE-2016-2105 DESCRIPTION: OpenSSL is vulnerable to a heap-based buffer overflow, caused by improper bounds checking by the EVP_EncodeUpdate() function. By sending an overly long argument, a remote attacker could overflow a buffer and execute arbitrary code on the system or cause the application to crash.
CVSS Base Score: 5.6
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/112855 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L

CVEID: CVE-2016-2106 DESCRIPTION: OpenSSL is vulnerable to a heap-based buffer overflow, caused by improper bounds checking by the EVP_EncryptUpdate() function. By sending an overly long argument, a remote attacker could overflow a buffer and execute arbitrary code on the system or cause the application to crash.
CVSS Base Score: 5.6
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/112856 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:L/A:L)

CVEID: CVE-2016-2109 DESCRIPTION: OpenSSL is vulnerable to a denial of service, caused by a memory allocation error. By reading specially crafted ASN.1 data from a BIO using functions such as d2i_CMS_bio(), an attacker could exploit this vulnerability to consume all available resources and exhaust memory.
CVSS Base Score: 5.3
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/112857 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L)

CVEID: CVE-2016-2176 DESCRIPTION: OpenSSL could allow a remote attacker to obtain sensitive information, By sending an overly long ASN.1 string to the X509_NAME_oneline() function, an attacker could exploit this vulnerability to return arbitrary stack data in the buffer.
CVSS Base Score: 5.3
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/112858 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)

Affected Products and Versions

OpenSSH for GPFS V3.5 for Windows

Remediation/Fixes

In GPFS V3.5.0.31 dated May 2016, IBM upgraded OpenSSH for GPFS on Windows to 7.2p2 and to use OpenSSL 1.0.2h to address these vulnerabilities. System administrators should update their systems to GPFS V3.5.0.31 by following the steps below.

1. Download the GPFS 3.5.0.31 update package dated May 2016 into any directory on your system from http://www-933.ibm.com/support/fixcentral/swg/selectFixes?parent=Cluster%2Bsoftware&product=ibm/power/IBM+General+Parallel+File+System&release=3.5.0&platform=Windows&function=all

2. Extract the contents of the ZIP archive so that the .msi file it includes is directly accessible to your system.

3. Follow the instructions in the README included in the update package in order to install the OpenSSH msi package. This updated OpenSSH 7.2.p2 msi package is built using OpenSSL 1.02h.

If GPFS multiclustering is configured on Windows nodes, upgrade all OpenSSL packages that may have been installed. The following can be done on a small group of nodes at each time (ensuring that quorum is maintained) to maintain file system availability:

a. Stop GPFS on the node
b. Install the version of OpenSSL
c. Restart GPFS on the node

Workarounds and Mitigations

None