[c-nsp] Cisco Security Advisory: Cisco Email Security Appliance Malformed DGN File Attachment Denial of Service Vulnerability

[Cisco Systems Product Security Incident Response Team]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

Cisco Security Advisory: Cisco Email Security Appliance Malformed DGN File Attachment Denial of Service Vulnerability

Advisory ID: cisco-sa-20161026-esa1

Revision 1.0

For Public Release 2016 October 26 16:00 UTC (GMT)

+---------------------------------------------------------------------

Summary
=======

A vulnerability in the email message filtering feature of Cisco AsyncOS Software for Cisco Email Security Appliances could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device.

The vulnerability exists because the message filtering feature of the affected software does not properly validate compressed message attachments that contain malformed Design (DGN) files. An attacker could exploit this vulnerability by sending a crafted email message, which has a compressed attachment containing a malformed DGN file, through an affected device. While the affected software filters the attachment, memory could be consumed at a high rate and ultimately exhausted, causing the filtering process to restart and resulting in a DoS condition. After the filtering process restarts, the software resumes filtering for the same attachment, causing the filtering process to exhaust memory and restart again. A successful exploit of this vulnerability could allow the attacker to cause a repeated DoS condition.

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: 

http://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20161026-esa1

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.5 (SunOS)
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=watm
-----END PGP SIGNATURE-----