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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2017.0152 Cisco Email Security Appliance Filter Bypass Vulnerability 19 January 2017 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco Email Security Appliance Publisher: Cisco Systems Operating System: Cisco Impact/Access: Reduced Security -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2017-3800 Original Bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170118-esa - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco Security Advisory Cisco Email Security Appliance Filter Bypass Vulnerability Medium Advisory ID: cisco-sa-20170118-esa First Published: 2017 January 18 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCuz16076 CVE-2017-3800 CWE-20 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-2017-3800 CWE-20 Summary A vulnerability in the content scanning engine of Cisco AsyncOS Software for Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to bypass configured message or content filters on the device. The vulnerability is due to incomplete input validation of email message attachments in different formats. An attacker could exploit this vulnerability by sending a crafted email message with an attachment to the ESA. An exploit could allow the attacker to bypass configured content or message filters configured on the ESA. This message filter bypass could allow email attachments that contain malware to pass through the targeted 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-20170118-esa Affected Products Vulnerable Products This vulnerability affects all releases prior to the first fixed release of Cisco AsyncOS Software for Cisco Email Security Appliances, both virtual and hardware appliances, if the software is configured to apply a message filter or content filter to incoming email attachments. The vulnerability is not limited to any specific rules or actions for a message filter or content filter. 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 Content Security Management Appliance, virtual and hardware versions Cisco Web Security 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 Cisco would like to thank security researcher Parvez Anwar for reporting this vulnerability. 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-20170118-esa Revision History Version Description Section Status Date 1.0 Initial public release. Final 2017-January-18 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. 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