CVE-2025-20115

high

Description

A vulnerability in confederation implementation for the Border Gateway Protocol (BGP) in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. This vulnerability is due to a memory corruption that occurs when a BGP update is created with an AS_CONFED_SEQUENCE attribute that has 255 autonomous system numbers (AS numbers). An attacker could exploit this vulnerability by sending a crafted BGP update message, or the network could be designed in such a manner that the AS_CONFED_SEQUENCE attribute grows to 255 AS numbers or more. A successful exploit could allow the attacker to cause memory corruption, which may cause the BGP process to restart, resulting in a DoS condition. To exploit this vulnerability, an attacker must control a BGP confederation speaker within the same autonomous system as the victim, or the network must be designed in such a manner that the AS_CONFED_SEQUENCE attribute grows to 255 AS numbers or more.

References

https://securityaffairs.com/175421/security/cisco-ios-xr-flaw-cve-2025-20115.html

https://www.bleepingcomputer.com/news/security/cisco-vulnerability-lets-attackers-crash-bgp-on-ios-xr-routers/

https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-bgp-dos-O7stePhX

https://blog.apnic.net/2024/09/02/crafting-endless-as-paths-in-bgp/

Details

Source: Mitre, NVD

Published: 2025-03-12

Updated: 2025-03-12

Risk Information

CVSS v2

Base Score: 7.8

Vector: CVSS2#AV:N/AC:L/Au:N/C:N/I:N/A:C

Severity: High

CVSS v3

Base Score: 8.6

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

Severity: High