A vulnerability in certain attachment detection mechanisms of Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to bypass the filtering functionality of an affected system. The vulnerability is due to the improper detection of content within executable (EXE) files. An attacker could exploit this vulnerability by sending a customized EXE file that is not recognized and blocked by the ESA. A successful exploit could allow an attacker to send email messages that contain malicious executable files to unsuspecting users. 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-20180815-esa-file-bypass
A vulnerability in certain attachment detection mechanisms of Cisco Email Security Appliances (ESA) could allow an unauthenticated, remote attacker to bypass the filtering functionality of an affected system.
The vulnerability is due to the improper detection of content within executable (EXE) files. An attacker could exploit this vulnerability by sending a customized EXE file that is not recognized and blocked by the ESA. A successful exploit could allow an attacker to send email messages that contain malicious executable files to unsuspecting users.
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-20180815-esa-file-bypass
Only products listed in the Vulnerable Products section of this advisory are known to be affected by this vulnerability.
There are no workarounds that address this vulnerability.
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.
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 Liam Romanis of InteliSecure EMEA 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 |
|---|---|---|---|---|
| 1.1 | Credited the external researcher who reported the vulnerability. | Source | Final | 2018-August-20 |
| 1.0 | Initial public release. | - | Final | 2018-August-15 |
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.
Vulmon