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AUSCERT External Security Bulletin Redistribution
ESB-2017.0152
Cisco Email Security Appliance Filter Bypass Vulnerability
19 January 2017
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AusCERT Security Bulletin Summary
---------------------------------
Product: Cisco Email Security Appliance
Publisher: Cisco Systems
Operating System: Cisco
Impact/Access: Reduced Security -- Remote/Unauthenticated
Resolution: Patch/Upgrade
CVE Names: CVE-2017-3800
Original Bulletin:
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170118-esa
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Cisco Security Advisory
Cisco Email Security Appliance Filter Bypass Vulnerability
Medium
Advisory ID:
cisco-sa-20170118-esa
First Published:
2017 January 18 16:00 GMT
Version 1.0:
Final
Workarounds:
No workarounds available
Cisco Bug IDs:
CSCuz16076
CVE-2017-3800
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:L/A:N/E:X/RL:X/RC:X
CVE-2017-3800
CWE-20
Summary
A vulnerability in the content scanning engine of Cisco AsyncOS Software
for Cisco Email Security Appliances (ESA) could allow an unauthenticated,
remote attacker to bypass configured message or content filters on the
device.
The vulnerability is due to incomplete input validation of email message
attachments in different formats. An attacker could exploit this
vulnerability by sending a crafted email message with an attachment to the
ESA. An exploit could allow the attacker to bypass configured content or
message filters configured on the ESA. This message filter bypass could
allow email attachments that contain malware to pass through the targeted
device.
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-20170118-esa
Affected Products
Vulnerable Products
This vulnerability affects all releases prior to the first fixed release of
Cisco AsyncOS Software for Cisco Email Security Appliances, both virtual
and hardware appliances, if the software is configured to apply a message
filter or content filter to incoming email attachments. The vulnerability
is not limited to any specific rules or actions for a message filter or
content filter.
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.
Cisco has confirmed that this vulnerability does not affect the following
products:
Cisco Content Security Management Appliance, virtual and hardware versions
Cisco Web Security Appliance, virtual and hardware versions
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
Cisco would like to thank security researcher Parvez Anwar for reporting
this vulnerability.
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-20170118-esa
Revision History
Version Description Section Status Date
1.0 Initial public release. Final 2017-January-18
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.
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