A vulnerability in the Cisco Discovery Protocol implementation for Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a reload on an affected device. The vulnerability is due to improper validation of string input from certain fields in Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges on an affected device. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).
The product uses a function that accepts a format string as an argument, but the format string originates from an external source.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ios_xr | Cisco | 6.6.0 (including) | 6.6.12 (excluding) |
| Ios_xr | Cisco | 7.0.0 (including) | 7.0.2 (excluding) |
When an attacker can modify an externally-controlled format string, this can lead to buffer overflows, denial of service, or data representation problems. It should be noted that in some circumstances, such as internationalization, the set of format strings is externally controlled by design. If the source of these format strings is trusted (e.g. only contained in library files that are only modifiable by the system administrator), then the external control might not itself pose a vulnerability.