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AUSCERT External Security Bulletin Redistribution
ESB-2017.0699
Cisco Nexus 9000 Series Switches Telnet Login Denial of
Service Vulnerability
16 March 2017
===========================================================================
AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco Nexus 9000 Series Switches
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2017-3879 CVE-2017-3878
Original Bulletin:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-nss
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-nss1
Comment: This bulletin contains two (2) Cisco Systems security advisories.
- --------------------------BEGIN INCLUDED TEXT--------------------
Cisco Security Advisory
Cisco Nexus 9000 Series Switches Telnet Login Denial of Service Vulnerability
Medium
Advisory ID: cisco-sa-20170315-nss
First Published: 2017 March 15 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds available
Cisco Bug IDs:
CSCux46778
CVE-2017-3878
CWE-119
CVSS Score:
Base 5.3, Temporal 5.3
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:X/RC:X
Summary
A vulnerability in the Telnet remote login functionality of Cisco NX-OS
Software running on Cisco Nexus 9000 Series Switches could allow an
unauthenticated, remote attacker to cause a Telnet process used for login
to terminate unexpectedly and the login attempt to fail. There is no impact
to user traffic flowing through the device.
The vulnerability is due to incomplete input validation of Telnet packet
headers. An attacker could exploit this vulnerability by sending a crafted
Telnet packet to an affected system during a remote Telnet login attempt. A
successful exploit could allow the attacker to cause the Telnet process on
the affected system to restart unexpectedly, resulting in a denial of
service (DoS) condition for the Telnet process.
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-20170315-nss
Affected Products
Vulnerable Products
This vulnerability affects Cisco Nexus 9000 Series Switches that are
running Cisco NX-OS Software and are configured to allow remote Telnet
connections to the device. 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.
Cisco Security Vulnerability Policy
To learn about Cisco security vulnerability disclosure policies and
publications, see the Security Vulnerability Policy. This document also
contains instructions for obtaining fixed software and receiving security
vulnerability information from Cisco.
URL
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-nss
Revision History
Version Description Section Status Date
1.0 Initial public release. Final 2017-March-15
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.
Cisco Security Vulnerability Policy
To learn about Cisco security vulnerability disclosure policies and
publications, see the Security Vulnerability Policy. This document also
contains instructions for obtaining fixed software and receiving security
vulnerability information from Cisco.
=========================================================================
Cisco Security Advisory
Cisco Nexus 9000 Series Switches Remote Login Denial of Service Vulnerability
Medium
Advisory ID: cisco-sa-20170315-nss1
First Published: 2017 March 15 16:00 GMT
Version 1.0: Final
Workarounds: No workarounds available
Cisco Bug IDs:
CSCuy25824
CVE-2017-3879
CWE-119
CVSS Score:
Base 5.3, Temporal 5.3
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L/E:X/RL:X/RC:X
Summary
A vulnerability in the remote login functionality for Cisco NX-OS Software
running on Cisco Nexus 9000 Series Switches could allow an unauthenticated,
remote attacker to cause a process used for login to terminate unexpectedly
and the login attempt to fail. There is no impact to user traffic flowing
through the device. The attacker could use either a Telnet or an SSH client
for the remote login attempt.
The vulnerability is due to improper handling of failed authentication
during login. An attacker could exploit this vulnerability by attempting to
log in remotely to the device. An exploit could allow the attacker to cause
a login process to terminate unexpectedly.
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-20170315-nss1
Affected Products
Vulnerable Products
This vulnerability affects Cisco Nexus 9000 Series Switches that are
running Cisco NX-OS Software and are configured to allow remote Telnet
connections to the device. 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.
Cisco Security Vulnerability Policy
To learn about Cisco security vulnerability disclosure policies and
publications, see the Security Vulnerability Policy. This document also
contains instructions for obtaining fixed software and receiving security
vulnerability information from Cisco.
URL
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-nss1
Revision History
Version Description Section Status Date
1.0 Initial public release. Final 2017-March-15
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.
Cisco Security Vulnerability Policy
To learn about Cisco security vulnerability disclosure policies and
publications, see the Security Vulnerability Policy. This document also
contains instructions for obtaining fixed software and receiving security
vulnerability information from Cisco.
- --------------------------END INCLUDED TEXT--------------------
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