Cisco Security Advisory
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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
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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://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170118-esa
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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 advisoryProducts 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
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There are no workarounds that address this vulnerability.
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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.
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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.
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Cisco would like to thank security researcher Parvez Anwar from Verizon for reporting this vulnerability.
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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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Show LessVersion Description Section Status Date 1.1 Added the name of the security researcher's company. Source Final 2017-January-19 1.0 Initial public release. — Final 2017-January-18
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