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-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA256 =========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2018.2648 Cisco Email Security Appliance URL Filtering Bypass Vulnerability 6 September 2018 =========================================================================== AusCERT Security Bulletin Summary --------------------------------- Product: Cisco Email Security Appliance Publisher: Cisco Systems Operating System: Cisco Impact/Access: Unauthorised Access -- Remote/Unauthenticated Resolution: Patch/Upgrade CVE Names: CVE-2018-0447 Original Bulletin: https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180905-esa-url-bypass - --------------------------BEGIN INCLUDED TEXT-------------------- Cisco Security Advisory Cisco Email Security Appliance URL Filtering Bypass Vulnerability Medium Advisory ID: cisco-sa-20180905-esa-url-bypass First Published: 2018 September 5 16:00 GMT Version 1.0: Final Workarounds: No workarounds available Cisco Bug IDs: CSCvj55728 CVE-2018-0447 CWE-284 CVSS Score: Base 5.3 CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N/E:X/RL:X/RC:X Summary o A vulnerability in the anti-spam protection mechanisms of Cisco AsyncOS Software for the Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass certain content filters on an affected device. The vulnerability is due to incomplete input and validation checking mechanisms for certain Sender Policy Framework (SPF) messages that are sent to an affected device. An attacker could exploit this vulnerability by sending a customized SPF packet to an affected device. If successful, an exploit could allow the attacker to bypass the URL filters that are configured for the affected device, which could allow malicious URLs to pass through 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-20180905-esa-url-bypass Affected Products o Vulnerable Products This vulnerability affects Cisco Email Security Appliance (ESA). For information about affected software releases, consult the Cisco bug ID(s) at the top of this advisory. Products Confirmed Not Vulnerable Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability. Workarounds o There are no workarounds that address this vulnerability. Fixed Software o 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 o 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 o This vulnerability was found during the resolution of a Cisco TAC support case. Cisco Security Vulnerability Policy o 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 o https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/ cisco-sa-20180905-esa-url-bypass Revision History o +---------+--------------------------+---------+--------+--------------------+ | Version | Description | Section | Status | Date | +---------+--------------------------+---------+--------+--------------------+ | 1.0 | Initial public release. | -- | Final | 2018-September-05 | +---------+--------------------------+---------+--------+--------------------+ Legal Disclaimer o 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. - --------------------------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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