A vulnerability in the External Border Gateway Protocol (eBGP) implementation of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability exists because eBGP traffic is mapped to a shared hardware rate-limiter queue. An attacker could exploit this vulnerability by sending large amounts of network traffic with certain characteristics through an affected device. A successful exploit could allow the attacker to cause eBGP neighbor sessions to be dropped, leading to a DoS condition in the network.
The product does not properly control the allocation and maintenance of a limited resource.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Nx-os | Cisco | 7.0(3)f1(1) (including) | 7.0(3)f1(1) (including) |
| Nx-os | Cisco | 7.0(3)f2(1) (including) | 7.0(3)f2(1) (including) |
| Nx-os | Cisco | 7.0(3)f2(2) (including) | 7.0(3)f2(2) (including) |
| Nx-os | Cisco | 7.0(3)f3(1) (including) | 7.0(3)f3(1) (including) |
| Nx-os | Cisco | 7.0(3)f3(2) (including) | 7.0(3)f3(2) (including) |
| Nx-os | Cisco | 7.0(3)f3(3) (including) | 7.0(3)f3(3) (including) |
| Nx-os | Cisco | 7.0(3)f3(3a) (including) | 7.0(3)f3(3a) (including) |
| Nx-os | Cisco | 7.0(3)f3(3c) (including) | 7.0(3)f3(3c) (including) |
| Nx-os | Cisco | 7.0(3)f3(4) (including) | 7.0(3)f3(4) (including) |
| Nx-os | Cisco | 7.0(3)f3(5) (including) | 7.0(3)f3(5) (including) |
| Nx-os | Cisco | 9.2(1) (including) | 9.2(1) (including) |
| Nx-os | Cisco | 9.2(2) (including) | 9.2(2) (including) |
| Nx-os | Cisco | 9.2(2t) (including) | 9.2(2t) (including) |
| Nx-os | Cisco | 9.2(2v) (including) | 9.2(2v) (including) |
| Nx-os | Cisco | 9.2(3) (including) | 9.2(3) (including) |
| Nx-os | Cisco | 9.2(4) (including) | 9.2(4) (including) |
| Nx-os | Cisco | 9.3(1) (including) | 9.3(1) (including) |
| Nx-os | Cisco | 9.3(2) (including) | 9.3(2) (including) |
| Nx-os | Cisco | 9.3(3) (including) | 9.3(3) (including) |
| Nx-os | Cisco | 9.3(4) (including) | 9.3(4) (including) |
| Nx-os | Cisco | 9.3(5) (including) | 9.3(5) (including) |
| Nx-os | Cisco | 9.3(6) (including) | 9.3(6) (including) |
| Nx-os | Cisco | 9.3(7) (including) | 9.3(7) (including) |
| Nx-os | Cisco | 9.3(7a) (including) | 9.3(7a) (including) |
| Nx-os | Cisco | 9.3(8) (including) | 9.3(8) (including) |
| Nx-os | Cisco | 9.3(9) (including) | 9.3(9) (including) |
| Nx-os | Cisco | 9.3(10) (including) | 9.3(10) (including) |
| Nx-os | Cisco | 9.3(11) (including) | 9.3(11) (including) |
| Nx-os | Cisco | 9.3(12) (including) | 9.3(12) (including) |
| Nx-os | Cisco | 10.1(1) (including) | 10.1(1) (including) |
| Nx-os | Cisco | 10.1(2) (including) | 10.1(2) (including) |
| Nx-os | Cisco | 10.1(2t) (including) | 10.1(2t) (including) |
| Nx-os | Cisco | 10.2(1) (including) | 10.2(1) (including) |
| Nx-os | Cisco | 10.2(1q) (including) | 10.2(1q) (including) |
| Nx-os | Cisco | 10.2(2) (including) | 10.2(2) (including) |
| Nx-os | Cisco | 10.2(3) (including) | 10.2(3) (including) |
| Nx-os | Cisco | 10.2(3t) (including) | 10.2(3t) (including) |
| Nx-os | Cisco | 10.2(3v) (including) | 10.2(3v) (including) |
| Nx-os | Cisco | 10.2(4) (including) | 10.2(4) (including) |
| Nx-os | Cisco | 10.2(5) (including) | 10.2(5) (including) |
| Nx-os | Cisco | 10.2(6) (including) | 10.2(6) (including) |
| Nx-os | Cisco | 10.3(1) (including) | 10.3(1) (including) |
| Nx-os | Cisco | 10.3(2) (including) | 10.3(2) (including) |
| Nx-os | Cisco | 10.3(3) (including) | 10.3(3) (including) |
| Nx-os | Cisco | 10.3(4a) (including) | 10.3(4a) (including) |
| Nx-os | Cisco | 10.3(99w) (including) | 10.3(99w) (including) |
| Nx-os | Cisco | 10.3(99x) (including) | 10.3(99x) (including) |
| Nx-os | Cisco | 10.4(1) (including) | 10.4(1) (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.