A vulnerability in the Decrypt for End-User Notification configuration parameter of Cisco AsyncOS Software for Cisco Web Security Appliances could allow an unauthenticated, remote attacker to connect to a secure website over Secure Sockets Layer (SSL) or Transport Layer Security (TLS), even if the WSA is configured to block connections to the website. The vulnerability is due to incomplete input validation of HTTP headers. An attacker could exploit this vulnerability by sending a crafted HTTP request through an affected device. A successful exploit could allow the attacker to connect to a website that should be blocked. 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-20161207-wsa1
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.
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.
| Version | Description | Section | Status | Date |
|---|---|---|---|---|
| 1.1 | Added a second Cisco bug identifier. | Product Attribute Set | Final | 2017-October-04 |
| 1.0 | Initial public release. | - | Final | 2016-December-07 |
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