Cisco IOS XR Software BGP MPLS-Based EVPN Denial of Service Vulnerability

A vulnerability in the Border Gateway Protocol (BGP) Multiprotocol Label Switching (MPLS)-based Ethernet VPN (EVPN) implementation of Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to trigger a denial of service (DoS) condition on an affected device.
The vulnerability is due to a logic error that occurs when the affected software processes specific EVPN routing information. An attacker could exploit this vulnerability by injecting malicious traffic patterns into the targeted EVPN network.

A successful exploit could result in a crash of the l2vpn_mgr process on Provider Edge (PE) device members of the same EVPN instance (EVI). On each of the affected devices, a crash could lead to system instability and the inability to process or forward traffic through the device, resulting in a DoS condition that would require manual intervention to restore normal operating conditions.

Cisco has released software updates that address this vulnerability. There are no workarounds that address this vulnerability.

This advisory is available at the following link:
https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-iosxr-evpn-dos [“https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-iosxr-evpn-dos”]