Cisco Intrusion Prevention System Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
A vulnerability in the SNMP code of Cisco Intrusion Prevention System (IPS) Software could allow an unauthenticated, remote attacker to cause the MainApp process to become unresponsive. This creates a denial of service (DoS) condition because the Cisco IPS sensor is not able to execute several critical tasks including alert notification, event store management, and sensor authentication. The Cisco IPS web server will also be unavailable while the MainApp process is unresponsive. Additionally, due to this general system failure, other processes such as the Analysis Engine may not function properly.
The vulnerability is due to improper handling of malformed SNMP packets. An attacker may exploit this vulnerability by sending malformed SNMP packets to the management interface of the affected system. The vulnerability can be triggered by SNMP version 1 (v1), v2, and v3. If the SNMP v3 user is configured with the noAuth option, the attacker could perform the attack without providing valid credentials. Cisco does not recommend configuring the SNMP v3 user with the noAuth option.
Traffic passing through the sensing interfaces will not trigger this vulnerability. If the Cisco IPS is configured in promiscuous mode, mitigation actions that require MainApp processing, such as shun or rate-limit, may be unavailable. If the Cisco IPS is configured in inline mode, the sensor may not correctly perform inspection and mitigation actions because the Analysis Engine process may not be functioning properly.
Cisco has confirmed the vulnerability in a security notice and software updates are available.
At the time this alert was first published, Cisco IPS Software versions 7.2(1)(E4) and prior were vulnerable. Later releases of Cisco IPS Software may also be vulnerable.
To exploit this vulnerability, an attacker may need access to trusted, internal networks to send malformed SNMP packets to the management interface of an affected device. This access requirement may reduce the possibility of a successful exploit.
Cisco indicates that software updates are available for bug ID CSCul49309; however, updates are not available for bug ID CSCum52355.
Cisco has released a security notice at the following link: CVE-2014-2103
Customers are advised to consult Cisco bug IDs CSCum52355 and CSCul49309 for a complete list of affected product versions.
An unauthenticated, remote attacker could exploit this vulnerability to cause the MainApp process on an affected device to become unresponsive, resulting in a DoS condition.
The vulnerability is due to improper handling of malformed SNMP packets by an affected device.
An attacker may exploit this vulnerability by sending malformed SNMP packets to the management interface of the affected system. If successful, the attacker could cause the MainApp process running on the targeted device to become unresponsive, resulting in a DoS condition.
Administrators are advised to apply the appropriate updates.
Administrators may consider disabling the SNMP server on affected devices.
Administrators are advised to allow only trusted users to have network access.
Administrators are advised to monitor affected systems.
Cisco customers with active contracts should contact their Cisco support team for assistance in upgrading to a software version that includes fixes for this vulnerability. Cisco customers without contracts may contact the Cisco Technical Assistance Center at 1-800-553-2447 or 1-408-526-7209 or via email at firstname.lastname@example.org for assistance.
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