A vulnerability in the Common Open Policy Service (COPS) of Cisco IOS XE Software for Cisco cBR-8 Converged Broadband Routers could allow an unauthenticated, remote attacker to cause resource exhaustion, resulting in a denial of service (DoS) condition. This vulnerability is due to a deadlock condition in the code when processing COPS packets under certain conditions. An attacker could exploit this vulnerability by sending COPS packets with high burst rates to an affected device. A successful exploit could allow the attacker to cause the CPU to consume excessive resources, which prevents other control plane processes from obtaining resources and results in a DoS.
The product does not properly acquire or release a lock on a resource, leading to unexpected resource state changes and behaviors.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ios_xe | Cisco | * | 16.12.1z1 (excluding) |
| Ios_xe | Cisco | 17.3.1x (including) | 17.3.1x (including) |
Locking is a type of synchronization behavior that ensures that multiple independently-operating processes or threads do not interfere with each other when accessing the same resource. All processes/threads are expected to follow the same steps for locking. If these steps are not followed precisely - or if no locking is done at all - then another process/thread could modify the shared resource in a way that is not visible or predictable to the original process. This can lead to data or memory corruption, denial of service, etc.