CVE-2020-26082: Cisco Security Advisory: Cisco Email Security Appliance Zip Content Filter Bypass Vulnerability

**

Summary

**

• A vulnerability in the zip decompression engine of Cisco AsyncOS Software for Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass content filters that are configured on an affected device.

  The vulnerability is due to improper handling of password-protected zip files. An attacker could exploit this vulnerability by sending a malicious file inside a crafted zip-compressed file to an affected device. A successful exploit could allow the attacker to bypass configured content filters that would normally drop the email.

  Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

  This advisory is available at the following link:
  https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-esa-zip-bypass-gbU4gtTg

**

Affected Products

**

• At the time of publication, this vulnerability affected Cisco ESA releases earlier than Release 13.5.2.

  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 section of this advisory are known to be affected by this vulnerability.

**

Workarounds

**

• There are no workarounds that address this vulnerability.

**

Fixed Software

**

• When considering software upgrades, customers are advised to regularly consult the advisories for Cisco products, which are available from the Cisco Security Advisories 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.

  Fixed Releases

  At the time of publication, Cisco ESA releases 13.5.2 and later contained the fix for this vulnerability.

  See the Details section in the bug ID(s) at the top of this advisory for the most complete and current information.

**

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 the 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.

**

Related to This Advisory

**

**

URL

**

**

Revision History

**

• Version

  Description

  Section

  Status

  Date

  1.0

  Initial public release.

  -

  Final

  2020-NOV-04

  Show Less

**

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.

**

Feedback

**