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AUSCERT External Security Bulletin Redistribution
ESB-2017.1575
Cisco Wide Area Application Services TCP Fragment Denial of
Service Vulnerability
22 June 2017
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AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco Wide Area Application Services
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Denial of Service -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2017-6721
Original Bulletin:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170621-waas
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Cisco Security Advisory
Cisco Wide Area Application Services TCP Fragment Denial of Service
Vulnerability
Medium
Advisory ID:
cisco-sa-20170621-waas
First Published:
2017 June 21 16:00 GMT
Version 1.0:
Final
Workarounds:
No workarounds available
Cisco Bug IDs:
CSCvc57428
CVE-2017-6721
CWE-20
CVSS Score:
Base 5.8, Temporal 5.8
CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L/E:X/RL:X/RC:X
CVE-2017-6721
CWE-20
Summary
A vulnerability in the ingress processing of fragmented TCP packets by
Cisco Wide Area Application Services (WAAS) could allow an unauthenticated,
remote attacker to cause the WAASNET process to restart unexpectedly,
causing a denial of service (DoS) condition.
The vulnerability is due to incomplete input validation of TCP packets when
a packet chain is fragmented. An attacker could exploit this vulnerability
by sending a crafted set of TCP fragments through an affected device. An
exploit could allow the attacker to cause a DoS condition due to a process
restarting unexpectedly. The WAAS could drop traffic during the brief time
that the WAASNET process is restarting.
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-20170621-waas
Affected Products
Vulnerable Products
This vulnerability affects Cisco Wide Area Application Services (WAAS). 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.
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.
Subscribe to Cisco Security Notifications
Subscribe
URL
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170621-waas
Revision History
Version Description Section Status Date
1.0 Initial public release. Final 2017-June-21
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.
Subscribe to Cisco Security Notifications
Subscribe
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