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             AUSCERT External Security Bulletin Redistribution

                               ESB-2018.0399
        Cisco IOS XR Software Routing and Forwarding Inconsistency
                      Denial of Service Vulnerability
                              8 February 2018

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

Product:           Cisco IOS XR
Publisher:         Cisco Systems
Operating System:  Cisco
Impact/Access:     Denial of Service -- Remote/Unauthenticated
Resolution:        Patch/Upgrade
CVE Names:         CVE-2018-0132  

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

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Cisco IOS XR Software Routing and Forwarding Inconsistency Denial of Service Vulnerability

Medium

Advisory ID: cisco-sa-20180207-iosxr

First Published: 2018 February 7 16:00 GMT

Version 1.0: Final

Workarounds: No workarounds available

Cisco Bug IDs: CSCus84718

CVSS Score: Base 6.8

CVE-2018-0132

CWE-119


Summary

A vulnerability in the forwarding information base (FIB) code of Cisco IOS XR
Software could allow an unauthenticated, remote attacker to cause inconsistency
between the routing information base (RIB) and the FIB, resulting in a denial of
service (DoS) condition.

The vulnerability is due to incorrect processing of extremely long routing
updates. An attacker could exploit this vulnerability by sending a large routing
update. A successful exploit could allow the attacker to trigger inconsistency
between the FIB and the RIB, resulting in a DoS condition.

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-iosxr


Affected Products

Vulnerable Products This vulnerability affects Cisco IOS XR 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 the resolution of a Cisco TAC support case.


URL

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


Revision History

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


Legal Disclaimer

THIS DOCUMENT IS PROVIDED ON AN "AS IS" BASIS AND DOES NOT IMPLY ANY KIND OF
GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS
FOR A PARTICULAR USE. YOUR USE OF THE INFORMATION ON THE DOCUMENT OR MATERIALS
LINKED FROM THE DOCUMENT IS AT YOUR OWN RISK. CISCO RESERVES THE RIGHT TO CHANGE
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.

- --------------------------END INCLUDED TEXT--------------------

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