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Security Bulletin: IBM i is affected by CVE-2018-20685, CVE-2019-6111, and CVE-2019-6109 vulnerabilities in OpenSSH.

Security Bulletin


Summary

OpenSSH is used by IBM i. IBM i has addressed the following vulnerabilities.

Vulnerability Details

CVEID: CVE-2019-6109
DESCRIPTION: OpenSSH could allow a remote attacker to conduct spoofing attacks, caused by missing character encoding in the progress display. A man-in-the-middle attacker could exploit this vulnerability to spoof scp client output.
CVSS Base Score: 3.1
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/155488 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:L/A:N)

CVEID: CVE-2019-6111
DESCRIPTION: OpenSSH could allow a remote attacker to overwrite arbitrary files on the system, caused by missing received object name validation by the scp client. The scp implementation accepts arbitrary files sent by the server and a man-in-the-middle attacker could exploit this vulnerability to overwrite unrelated files.
CVSS Base Score: 5.3
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/155486 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:N/I:H/A:N)

CVEID: CVE-2018-20685
DESCRIPTION: OpenSSH could allow a remote attacker to bypass security restrictions, caused by directory name validation by scp.c in the scp client. A man-in-the-middle attacker could exploit this vulnerability using the filename of . or an empty filename to bypass access restrictions and modify permissions of the target directory.
CVSS Base Score: 7.5
CVSS Temporal Score: See https://exchange.xforce.ibmcloud.com/vulnerabilities/155484 for the current score
CVSS Environmental Score*: Undefined
CVSS Vector: (CVSS:3.0/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H)

Affected Products and Versions

Releases 7.1, 7.2, and 7.3 of IBM i are affected.

Remediation/Fixes

The issue can be fixed by applying a PTF to IBM i.

Releases 7.1, 7.2, and 7.3 of IBM i are supported and will be fixed.

The IBM i PTF numbers are:
Release 7.1  – SI69329
Release 7.2 & 7.3  – SI69336

https://www-945.ibm.com/support/fixcentral/

Important note: IBM recommends that all users running unsupported versions of affected products upgrade to supported and fixed version of affected products.

Workarounds and Mitigations

None

Get Notified about Future Security Bulletins

Reference

Complete CVSS v3 Guide
On-line Calculator v3

Related Information

IBM Secure Engineering Web Portal
IBM Product Security Incident Response Blog

Change History

02 April 2019: CVE-2019-6110 was removed from the bulletin since a fix was not made by OpenSSH.
29 March 2019: Original Version Published

*The CVSS Environment Score is customer environment specific and will ultimately impact the Overall CVSS Score. Customers can evaluate the impact of this vulnerability in their environments by accessing the links in the Reference section of this Security Bulletin.

Disclaimer

According to the Forum of Incident Response and Security Teams (FIRST), the Common Vulnerability Scoring System (CVSS) is an "industry open standard designed to convey vulnerability severity and help to determine urgency and priority of response." IBM PROVIDES THE CVSS SCORES ""AS IS"" WITHOUT WARRANTY OF ANY KIND, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. CUSTOMERS ARE RESPONSIBLE FOR ASSESSING THE IMPACT OF ANY ACTUAL OR POTENTIAL SECURITY VULNERABILITY.


Cross reference information
Product Component Platform Version Edition
IBM i 7.1 IBM i 7.1
IBM i 7.2 IBM i 7.2
IBM i 7.3 IBM i 7.3

Document information

More support for: IBM i

Software version: 7.1, 7.2, 7.3

Operating system(s): IBM i

Reference #: 0731015

Modified date: 02 April 2019