A vulnerability in the 802.11r Fast Transition feature set of Cisco IOS Access Points (APs) Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition on an affected device. The vulnerability is due to a corruption of certain timer mechanisms triggered by specific roaming events. This corruption will eventually cause a timer crash. An attacker could exploit this vulnerability by sending malicious reassociation events multiple times to the same AP in a short period of time, causing a DoS condition on the affected AP.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Access_points | Cisco | 8.0(140.0) (including) | 8.0(140.0) (including) |
| Access_points | Cisco | 8.2(141.0) (including) | 8.2(141.0) (including) |
| Access_points | Cisco | 8.2(151.0) (including) | 8.2(151.0) (including) |
| Access_points | Cisco | 8.3(102.0) (including) | 8.3(102.0) (including) |
| Access_points | Cisco | 8.3(112.0) (including) | 8.3(112.0) (including) |
| Access_points | Cisco | 8.3(114.74) (including) | 8.3(114.74) (including) |
| Access_points | Cisco | 15.3(3)jd (including) | 15.3(3)jd (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.