A vulnerability in the IP fragment-handling implementation of Cisco Adaptive Security Appliance (ASA) Software and Cisco Firepower Threat Defense (FTD) Software could allow an unauthenticated, remote attacker to cause a memory leak on an affected device. This memory leak could prevent traffic from being processed through the device, resulting in a denial of service (DoS) condition. The vulnerability is due to improper error handling when specific failures occur during IP fragment reassembly. An attacker could exploit this vulnerability by sending crafted, fragmented IP traffic to a targeted device. A successful exploit could allow the attacker to continuously consume memory on the affected device and eventually impact traffic, resulting in a DoS condition. The device could require a manual reboot to recover from the DoS condition. Note: This vulnerability applies to both IP Version 4 (IPv4) and IP Version 6 (IPv6) traffic.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Firepower_threat_defense | Cisco | 6.6.0.1 (including) | 6.6.0.1 (including) |
| Adaptive_security_appliance_software | Cisco | 9.8.4.22 (including) | 9.8.4.22 (including) |
| Adaptive_security_appliance_software | Cisco | 9.8.4.25 (including) | 9.8.4.25 (including) |
| Adaptive_security_appliance_software | Cisco | 9.12.4.2 (including) | 9.12.4.2 (including) |
| Adaptive_security_appliance_software | Cisco | 9.12.4.3 (including) | 9.12.4.3 (including) |
| Adaptive_security_appliance_software | Cisco | 9.13.1.12 (including) | 9.13.1.12 (including) |
| Adaptive_security_appliance_software | Cisco | 9.14.1.15 (including) | 9.14.1.15 (including) |
Mitigation of resource exhaustion attacks requires that the target system either:
The first of these solutions is an issue in itself though, since it may allow attackers to prevent the use of the system by a particular valid user. If the attacker impersonates the valid user, they may be able to prevent the user from accessing the server in question.
The second solution is simply difficult to effectively institute – and even when properly done, it does not provide a full solution. It simply makes the attack require more resources on the part of the attacker.