ESB-2018.0400 - [Cisco] Cisco IOS and IOS XE: Overwrite arbitrary files - Existing account - 2018-02-08


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             AUSCERT External Security Bulletin Redistribution

                               ESB-2018.0400
Cisco IOS and IOS XE Software Diagnostic Shell Path Traversal Vulnerability
                              8 February 2018

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        AusCERT Security Bulletin Summary
        ---------------------------------

Product:           Cisco IOS
                   Cisco IOS XE
Publisher:         Cisco Systems
Operating System:  Cisco
Impact/Access:     Overwrite Arbitrary Files -- Existing Account
Resolution:        Patch/Upgrade
CVE Names:         CVE-2018-0123  

Original Bulletin: 
   https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180207-ios

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Cisco IOS and IOS XE Software Diagnostic Shell Path Traversal Vulnerability

Medium

Advisory ID: cisco-sa-20180207-ios

First Published: 2018 February 7 16:00 GMT

Version 1.0: Final

Workarounds: No workarounds available

Cisco Bug IDs: CSCvg41950

CVSS Score: Base 4.4

CVE-2018-0123

CWE-22


Summary

A vulnerability in the diagnostic shell for Cisco IOS and IOS XE Software could
allow an authenticated, local attacker to use certain diagnostic shell commands
that can overwrite system files. These system files may be sensitive and should
not be able to be overwritten by a user of the diagnostic shell.

The vulnerability is due to lack of proper input validation for certain
diagnostic shell commands. An attacker could exploit this vulnerability by
authenticating to the device, entering the diagnostic shell, and providing
crafted user input to commands at the local diagnostic shell CLI. Successful
exploitation could allow the attacker to overwrite system files that should be
restricted.

There are no workarounds that address this vulnerability.

This advisory is available at the following link:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180207-ios


Affected Products

Vulnerable Products This vulnerability affects Cisco IOS and IOS XE Software.
For information about affected software releases, consult the Cisco bug ID(s) at
the top of this advisory.  Products Confirmed Not Vulnerable No other Cisco
products are currently known to be affected by this vulnerability.


Workarounds

There are no workarounds that address this vulnerability.


Fixed Software

For information about fixed software releases, consult the Cisco bug ID(s) at
the top of this advisory.

When considering software upgrades, customers are advised to regularly consult
the advisories for Cisco products, which are available from the Cisco Security
Advisories and Alerts page, to determine exposure and a complete upgrade
solution.

In all cases, customers should ensure that the devices to be upgraded contain
sufficient memory and confirm that current hardware and software configurations
will continue to be supported properly by the new release. If the information is
not clear, customers are advised to contact the Cisco Technical Assistance
Center (TAC) or their contracted maintenance providers.


Exploitation and Public Announcements

The Cisco Product Security Incident Response Team (PSIRT) is not aware of any
public announcements or malicious use of the vulnerability that is described in
this advisory.


Source

This vulnerability was found during internal security testing.


URL

https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180207-ios


Revision History

+---------+---------------------------+---------+--------+-------------------+
| Version |        Description        | Section | Status |       Date        |
+---------+---------------------------+---------+--------+-------------------+
| 1.0     | Initial public release.   | -       | Final  | 2018-February-07  |
+---------+---------------------------+---------+--------+-------------------+


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FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS
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OR UPDATE THIS DOCUMENT AT ANY TIME.

A standalone copy or paraphrase of the text of this document that omits the
distribution URL is an uncontrolled copy and may lack important information or
contain factual errors. The information in this document is intended for end
users of Cisco products.

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