Cisco Security Advisory
Click Icon to Copy Verbose Score
AV:N/AC:L/Au:N/C:N/I:N/A:P/E:F/RL:OF/RC:C
-
A vulnerability in the clustering component of Cisco AsyncOS for Cisco Email Security Appliance (ESA) and Cisco Web Security Appliance (WSA) could allow an unauthenticated, remote attacker to cause the device to become unresponsive on the clustering and SSH configured ports.
The vulnerability is due to improper handling of packets sent at a high rate when the system is configured for clustering. An attacker could exploit this vulnerability by sending packets to the targeted system at a high rate. An exploit could allow the attacker to cause the affected system to become unresponsive on the clustering and SSH configured ports, causing all new connections to these ports to fail. A reload is required to restore normal operational behavior.
Cisco has confirmed the vulnerability and released software updates.
To exploit this vulnerability, an attacker would need to send packets to the affected device at a high rate, making exploitation more difficult in environments that restrict access to untrusted sources.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
-
Cisco has released bug IDs CSCur13704, CSCuq05636, CSCuv43307, and CSCuv99383 for registered users, which contains additional details and an up-to-date list of affected product versions.
Vulnerable Products
At the time this alert was first published, Cisco ESA releases 8.5.6-073, 8.5.6-074, and 9.0.0-461 and Cisco WSA release 8.5.2-027 were vulnerable. Later releases of Cisco ESA and Cisco WSA may also be vulnerable.Products Confirmed Not Vulnerable
No other Cisco products are currently known to be affected by these vulnerabilities.
-
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to monitor affected systems.
-
Cisco customers with active contracts can obtain updates through the Software Center at the following link: Cisco. Cisco customers without contracts can obtain upgrades by contacting the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at tac@cisco.com.
-
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.
-
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.
-
Show LessVersion Description Section Status Date 2.0 IntelliShield has updated this alert to include additional information and affected releases related to the Cisco AsyncOS for Cisco Email Security Appliance cluster denial of service vulnerability. NA Final 2015-Jul-27 1.0 Cisco AsyncOS for Cisco Email Security Appliance contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available. NA Final 2015-Jul-10
-
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 stand-alone 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.