A vulnerability in the scanning engines of Cisco AsyncOS Software for Cisco Secure Web Appliance, formerly known as Cisco Web Security Appliance (WSA), could allow an unauthenticated, remote attacker to bypass a configured rule, thereby allowing traffic onto a network that should have been blocked. This vulnerability exists because malformed, encoded traffic is not properly detected. An attacker could exploit this vulnerability by connecting through an affected device to a malicious server and receiving malformed HTTP responses. A successful exploit could allow the attacker to bypass an explicit block rule and receive traffic that should have been rejected by the 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-wsa-bypass-bwBfugek Attention: Simplifying the Cisco portfolio includes the renaming of security products under one brand: Cisco Secure. For more information, see Meet Cisco Secure.
A vulnerability in the scanning engines of Cisco AsyncOS Software for Cisco Secure Web Appliance, formerly known as Cisco Web Security Appliance (WSA), could allow an unauthenticated, remote attacker to bypass a configured rule, thereby allowing traffic onto a network that should have been blocked.
This vulnerability exists because malformed, encoded traffic is not properly detected. An attacker could exploit this vulnerability by connecting through an affected device to a malicious server and receiving malformed HTTP responses. A successful exploit could allow the attacker to bypass an explicit block rule and receive traffic that should have been rejected by the 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-wsa-bypass-bwBfugek
Attention: Simplifying the Cisco portfolio includes the renaming of security products under one brand: Cisco Secure. For more information, see Meet Cisco Secure.
At the time of publication, this vulnerability affected Cisco Secure Web Appliance, both virtual and hardware versions.
Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.
Cisco has confirmed that this vulnerability does not affect the following Cisco products:
There are no workarounds that address this vulnerability.
When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories 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.
For information about fixed software releases, see the Details section in the bug ID(s) at the top of this advisory.
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.
Cisco would like to thank scanplus GmbH for reporting this vulnerability.
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 |
---|---|---|---|---|
1.0 | Initial public release. | - | Final | 2022-OCT-05 |
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