Cisco ASA CX Context-Aware Security software and Cisco Prime Security Manager contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are available.
Cisco ASA CX Context-Aware Security software and Cisco Prime Security Manager (PRSM) contain a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on a targeted device.
The vulnerability is due to improper log management by the affected software. An unauthenticated, remote attacker could exploit this vulnerability by sending a high rate of packets to the management interface of the Cisco ASA CX or Cisco PRSM device. A successful exploit of a Cisco ASA CX device could allow the attacker to cause the device to stop processing legitimate user traffic and affect user access to the management interface. A successful exploit of a Cisco PRSM device could cause the device to become unresponsive to legitimate user traffic and unavailable for managing Cisco ASA CX devices.
Cisco has confirmed this vulnerability and released software updates.
Cisco ASA CX Context-Aware Security and PRSM software versions prior to 9.0.2-103 are vulnerable.
Attackers do not require authentication to exploit this vulnerability, but may require access to trusted, internal networks to establish a connection with the affected device. This access requirement may reduce the likelihood of a successful exploit.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
The Cisco ASA CX Context-Aware Security add-on services module extends the ASA platform with context-aware capabilities. The Cisco Prime Security Manager (PRSM) is the management platform for managing multiple Cisco ASA CX devices.
If a customer device has been affected by this vulnerability and /var/log is 100 percent utilized, the customer should contact the Cisco Technical Assistance Center; applying the software updates will not be sufficient to restore service.
An unauthenticated, remote attacker could exploit this vulnerability to cause the Cisco ASA CX or PRSM device to stop responding to legitimate user traffic and affect user access to the management interface and tool for managing ASA CX devices.
The vulnerability exists because the affected software improperly manages log retention, allowing the /var/log partition to grow until it is 100 percent utilized.
An unauthenticated, remote attacker could exploit this
vulnerability by sending a high rate of packets to the management
interface of the Cisco ASA CX or Cisco PRSM device. When the packets are processed by the affected software, the /var/log partition could completely fill. This condition could cause the device to become unresponsive to legitimate user traffic and affect user access to the management interface of an ASA CX device, or it could cause a PRSM device to become unresponsive and unavailable for managing an ASA CX device. Successful exploitation could allow an attacker to consume excessive system resources, resulting in a DoS condition.
Administrators are advised to apply the appropriate updates.
Administrators may consider using IP-based access control lists (ACLs) to allow only trusted systems to access the affected systems.
Administrators are advised to monitor critical systems.
If customers have been impacted by this vulnerability on a Cisco
ASA CX device and user traffic has been interrupted, administrators may consider removing the Modular Policy Framework (MPF)
configuration on the Cisco ASA that directs user traffic to the ASA CX module. Removing the MPF configuration will cause user traffic to bypass the ASA CX module and flow though the Cisco ASA, restoring user service.
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 email@example.com.
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