Cisco Small Business Switches contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition on a targeted device. Updates are available.
Cisco Small Business Switches contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition to features that rely on SSH or SSL protocols.
The vulnerability is due to the processing flaw in malformed packets in the code used by SSH and SSL. An unauthenticated, remote attacker could exploit this vulnerability by sending malformed SSH or SSL packets to the device. An exploit could allow the attacker to cause a denial of service for the features requiring SSH or SSL support.
Cisco has confirmed this vulnerability and released updated software.
The following Cisco Small Business Series Switches are vulnerable:
Cisco Small Business 200 Series Smart Switch versions 188.8.131.52 and prior
Cisco Small Business 300 Series Managed Switch versions 184.108.40.206 and prior
Cisco Small Business 500 Series Stackable Managed Switch version 220.127.116.11 and prior
To exploit this vulnerability, an attacker must be able to send crafted SSH or SSL packets to the targeted device which may require the attacker to have access to trusted, internal networks, decreasing the likelihood of a successful attack.
The vulnerability does not affect the entire device. Features that need the SSL/TLS layer to encrypt data such as SSH, HTTPS, and Secure Sensitive Data are affected.
Cisco would like to thank Hisashi Kojima and Masahiro Nakada of Fujitsu Laboratories LTD for discovering this vulnerability.
Cisco has confirmed this vulnerability in the following Cisco bug ID: CSCua30246
An unauthenticated, remote attacker could exploit this vulnerability by sending crafted SSH or SSL packets to a vulnerable device. Successful exploitation could cause features utilizing the SSL/TLS layer on the vulnerable device to become unresponsive, resulting in a DoS condition.
The vulnerability is due to the improper processing of malformed SSH or SSL packets by the affected software.
An unauthenticated, remote attacker could exploit this vulnerability by sending malformed SSH or SSL packets to the targeted device. Successful exploitation could allow the attacker to cause a DoS condition for the features requiring SSH or SSL support on a targeted device.
Administrators are advised to apply the appropriate updates.
Administrators are advised to allow only trusted users to have network access.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
Administrators are advised to monitor critical 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 e-mail at firstname.lastname@example.org.
The security vulnerability applies to the following combinations of products.
Cisco Small Business 200 Series Smart Switches
1.1 .0.73, .1.8, .2.0 | 1.2 .0.97, .7.76
Cisco Small Business 300 Series Managed Switches
1.1 .0.73, .1.8, .2.0 | 1.2 .0.97, .7.76
Cisco Small Business 500 Series Stackable Managed Switches
1.2 .0.97, .7.76
Alerts and bulletins on the Cisco Security Intelligence Operations Portal are highlighted by analysts in the
Cisco Threat Operations Center and represent a subset of the comprehensive content that is available through Cisco Security IntelliShield Alert Manager Service.
This customizable threat and vulnerability alert service provides security staff with access to timely, accurate, and credible information about threats and vulnerabilities that may affect their environment.
The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.