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.
Description
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.
Warning Indicators
The following Cisco Small Business Series Switches are vulnerable:
Cisco Small Business 200 Series Smart Switch versions 1.2.7.76 and prior
Cisco Small Business 300 Series Managed Switch versions 1.2.7.76 and prior
Cisco Small Business 500 Series Stackable Managed Switch version 1.2.7.76 and prior
IntelliShield Analysis
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.
Vendor Announcements
Cisco has confirmed this vulnerability in the following Cisco bug ID: CSCua30246
Impact
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.
Technical Information
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.
Safeguards
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.
Patches/Software
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 tac@cisco.com.
The security vulnerability applies to the following combinations of products.
Primary Products:
Cisco
Cisco Small Business 200 Series Smart Switches
1.1 .0.73, .1.8, .2.0 | 1.2 .0.97, .7.76
Cisco
Cisco Small Business 300 Series Managed Switches
1.1 .0.73, .1.8, .2.0 | 1.2 .0.97, .7.76
Cisco
Cisco Small Business 500 Series Stackable Managed
1.2 .0.97, .7.76
Associated Products:
N/A
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