Protect yourself against future threats.
-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2017.0686 Cisco Web Security Appliance URL Filtering Bypass Vulnerability 16 March 2017 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco Web Security Appliance (WSA) Publisher: Cisco Systems Operating System: Cisco Impact/Access: Unauthorised Access -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2017-3870 Original Bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-wsa - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco Security Advisory Cisco Web Security Appliance URL Filtering Bypass Vulnerability Medium Advisory ID: cisco-sa-20170315-wsa First Published: 2017 March 15 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCvc69700 CVE-2017-3870 CWE-119 CVSS Score: Base 5.8, Temporal 5.8 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 CVE-2017-3870 CWE-119 Summary A vulnerability in the URL filtering feature of Cisco AsyncOS Software for Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to bypass a configured URL filter rule. The vulnerability is due to incomplete validation of the HTTP request. An attacker could exploit this vulnerability by sending a crafted HTTP request through the targeted device. An exploit could allow the attacker to bypass a configured URL filter. 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-20170315-wsa Affected Products Vulnerable Products This vulnerability affects all releases prior to the first fixed release of Cisco AsyncOS Software for Cisco Web Security Appliance (WSA), both virtual and hardware appliances, that are configured with URL filters for email scanning. For information about affected software releases, consult the Cisco bug ID (s) at the top of this advisory. Products 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 Email Security Appliance, virtual and hardware versions Cisco Content Security Management Appliance, virtual and hardware versions Workarounds There are no workarounds that address this vulnerability. Fixed Software 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. Exploitation and Public Announcements 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. Source This vulnerability was found during resolution of a Cisco TAC support case. Cisco Security Vulnerability Policy 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. URL https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170315-wsa Revision History Version Description Section Status Date 1.0 Initial public release. Final 2017-March-15 Legal Disclaimer 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. Cisco Security Vulnerability Policy 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. - --------------------------END INCLUDED TEXT-------------------- You have received this e-mail bulletin as a result of your organisation's registration with AusCERT. The mailing list you are subscribed to is maintained within your organisation, so if you do not wish to continue receiving these bulletins you should contact your local IT manager. If you do not know who that is, please send an email to auscert@auscert.org.au and we will forward your request to the appropriate person. NOTE: Third Party Rights This security bulletin is provided as a service to AusCERT's members. As AusCERT did not write the document quoted above, AusCERT has had no control over its content. The decision to follow or act on information or advice contained in this security bulletin is the responsibility of each user or organisation, and should be considered in accordance with your organisation's site policies and procedures. AusCERT takes no responsibility for consequences which may arise from following or acting on information or advice contained in this security bulletin. NOTE: This is only the original release of the security bulletin. It may not be updated when updates to the original are made. If downloading at a later date, it is recommended that the bulletin is retrieved directly from the author's website to ensure that the information is still current. Contact information for the authors of the original document is included in the Security Bulletin above. If you have any questions or need further information, please contact them directly. Previous advisories and external security bulletins can be retrieved from: http://www.auscert.org.au/render.html?cid=1980 =========================================================================== Australian Computer Emergency Response Team The University of Queensland Brisbane Qld 4072 Internet Email: auscert@auscert.org.au Facsimile: (07) 3365 7031 Telephone: (07) 3365 4417 (International: +61 7 3365 4417) AusCERT personnel answer during Queensland business hours which are GMT+10:00 (AEST). On call after hours for member emergencies only. =========================================================================== -----BEGIN PGP SIGNATURE----- Comment: http://www.auscert.org.au/render.html?it=1967 iQIVAwUBWMnceox+lLeg9Ub1AQh2uw/8CWARcByW0xfwCK9YFU3cRPSWEye957Lj t3icTQTrjt7l5nAFM5HZv7jop7cKJgwYFTDtkBA7K3eUleujrkAEM++0unZj6TUI FEuvwbdqY+GgMMb58L4yf57zA15sHEs5OKS3YPDOmz+xxNWRm5j8rPHR93byI0Cs Yb9KuKK+F4M8cQBdRkjqqRkrSknCfDJHKSMaSaVt80bcIeCPB20k78JraWccIy+5 S6V4u06o9jX3Sw8mrb04kT0I82q1LYgjwWy5382eOUGeV7oFOD8fTeNlE/ciUNGC bFYeCsQNBbnFzMu7+GWF3IECFVQ5IkYnPPm8odaBP2wikPB9K0lnJSlTMq1awHII GqSh5yFN8vFVBubHml0oothfqYRNi0NTowC/Hp3dSiJhuKAwWUwavQ06ciKWzvuh 9GzYOhFt/AZXk0ub/YKuLogkHHCOTDz8ZnkIroBcaCQMiNE/io7eI30Ua6QL/Nyh 2oblejoXHXMQf5YymHOjMaMUtXxLBKRxcxGsrNgSuUKafHHL4xlJQDYBOjYgga85 9ywCCO7vyWU6MA9BBipcRI/c8ayQa4ZwUO+a7PHdeZRPW9Z+E9g0AePJ+SgVEi3m zcqaf+qqsre3oJwKhX+kr2QhGaH2hlfb/Ru/TweVjn7UyDdbPiHbs+MFznwEn358 N2jdLS6BbiY= =3wsV -----END PGP SIGNATURE-----