Cisco Secure Web Appliance Content Encoding Filter Bypass Vulnerabilities
Cisco Security Advisory
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More information can be found in Cisco Security Vulnerability Policy available at http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html
cisco-sa-wsa-bypass-bwBfugek
Final
2.0
1.0
2022-10-05T15:38:03
Initial public release.
1.1
2023-02-15T17:34:08
Added fixed release information. Added references to the Fixed Software section.
1.2
2023-03-02T20:18:46
Added details about newly introduced vulnerabilities and future fix plans for those vulnerabilities.
2.0
2023-04-03T13:46:35
Added CVE-2023-20099. Added Cisco bug ID CSCwe16408. Updated the summary and the fixed release table.
2022-10-05T16:00:00
2023-04-03T13:46:35
TVCE
Multiple vulnerabilities in the scanning engines of Cisco AsyncOS Software for Cisco Secure Web Appliance, formerly 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.
These vulnerabilities exist because malformed, encoded traffic is not properly detected. An attacker could exploit these vulnerabilities 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.
Cisco has released software updates that address these vulnerabilities. There are no workarounds that address these vulnerabilities.
This advisory is available at the following link: https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wsa-bypass-bwBfugek ["https://sec.cloudapps.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 ["https://www.cisco.com/c/en/us/products/security/secure-names.html"].
At the time of publication, these vulnerabilities affected Cisco Secure Web Appliance, both virtual and hardware versions.
For information about which Cisco software releases were vulnerable at the time of publication, see the Fixed Software ["#fs"] section of this advisory. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.
Only products listed in the Vulnerable Products ["#vp"] section of this advisory are known to be affected by these vulnerabilities.
Cisco has confirmed that these vulnerabilities do not affect the following Cisco products:
Email Security Appliance (ESA), both virtual and hardware appliances
Secure Email and Web Manager, both virtual and hardware appliances
There are no workarounds that address these vulnerabilities.
When considering software upgrades ["https://sec.cloudapps.cisco.com/security/center/resources/security_vulnerability_policy.html#fixes"], customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories page ["https://www.cisco.com/go/psirt"], 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.
Fixed Releases
At the time of publication, the release information in the following table was accurate. See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.
The left column lists Cisco software releases, and the right column indicates whether a release was affected by the vulnerabilities that are described in this advisory and which release included the fix for these vulnerabilities.
Cisco AsyncOS Release First Fixed Release 11.7 and earlier Not vulnerable. 11.8 Migrate to a fixed release. 12.0 Migrate to a fixed release. 12.5 Migrate to a fixed release. 14.0 14.0.4 14.5 14.5.1-016
The Cisco Product Security Incident Response Team (PSIRT) validates only the affected and fixed release information that is documented in this advisory.
To learn about Cisco security vulnerability disclosure policies and publications, see the Security Vulnerability Policy ["http://www.cisco.com/web/about/security/psirt/security_vulnerability_policy.html"]. This document also contains instructions for obtaining fixed software and receiving security vulnerability information from Cisco.
The Cisco Product Security Incident Response Team (PSIRT) is not aware of any public announcements or malicious use of the vulnerabilities that are described in this advisory.
Cisco would like to thank scanplus GmbH for reporting these vulnerabilities.
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.
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wsa-bypass-bwBfugek
Cisco Secure Web Appliance Content Encoding Filter Bypass Vulnerabilities
Cisco Secure Web Appliance
Cisco Secure Web Appliance Content Encoding Filter Bypass Vulnerability
CSCwe16408
CSCwe16408
Complete.
CVE-2023-20099
CVRFPID-189789
5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
There are no workarounds that address these vulnerabilities.
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wsa-bypass-bwBfugek
Cisco Secure Web Appliance Content Encoding Filter Bypass Vulnerabilities
Cisco WSA secuerity bypass
CSCwc54898
CSCwc54898
Complete.
CVE-2022-20952
CVRFPID-189789
5.3
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
There are no workarounds that address these vulnerabilities.
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-wsa-bypass-bwBfugek
Cisco Secure Web Appliance Content Encoding Filter Bypass Vulnerabilities