Cisco Security Advisory
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AV:N/AC:M/Au:N/C:N/I:P/A:N/E:F/RL:OF/RC:C
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A vulnerability in the update functionality of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA), Cisco Web Security Appliance (WSA), and Cisco Content Management Security Appliance (SMA) could allow an unauthenticated, remote attacker to impersonate the update server.
The vulnerability is due to a lack of certificate validation during the HTTPS connection toward the repository from which the update manifests are retrieved. An attacker could exploit this vulnerability by performing a man-in-the-middle attack (such as DNS hijacking) and impersonating the update server.
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-20161207-asyncos
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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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This vulnerability was found during the resolution of support cases.
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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 1.0 Initial public release. — Final 2016-December-07
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