Cisco Adaptive Security Appliance Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service condition. Updates are not available.
Cisco Adaptive Security Appliance (ASA) Software contains a vulnerability that could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition.
The vulnerability is due to the improper implementation of the Network Address Translation (NAT) process by the affected software. An unauthenticated, remote attacker could exploit this vulnerability by sending crafted packets to the targeted device. If successful, an attacker could cause a delay in new valid connections until the invalid entries expire, resulting in a DoS condition.
Cisco has confirmed the vulnerability; however, software updates are not available.
At the time this alert was first published, Cisco ASA Software versions 8.4.5 and prior were vulnerable. Later versions of Cisco ASA Software may also be affected.
Customers are advised to review the bug report in the vendor announcements section for a current list of affected versions.
Cisco indicates through the CVSS score that functional exploit code exists; however, the code is not known to be publicly available.
An unauthenticated, remote attacker could exploit this vulnerability to consume part of the available memory allocated for the xlates table. As a result, new valid connections cannot be established until invalid entries expire, resulting in a DoS condition.
The vulnerability is due to the improper implementation of the NAT process by the affected software. The incorrect handling of crafted packets could delay new connection entries to the xlates table used by the affected software from being established.
An unauthenticated, remote attacker could exploit this vulnerability by sending crafted packets to a targeted device. When processed, the crafted packets could allow the attacker to consume available memory allocated for the xlates table used by the affected software. If successful, the attacker could cause a delay in new valid connections until the invalid entries expire, resulting in a DoS condition.
Administrators are advised to contact the vendor regarding future updates and releases.
Administrators are advised to allow only trusted users to have network access.
Administrators can help protect affected systems from external attacks by using a solid firewall strategy.
Administrators are advised to implement an intrusion prevention system (IPS) or intrusion detection system (IDS) to help detect and prevent attacks that attempt to exploit this vulnerability.
Administrators are advised to monitor affected systems.
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