Attack vector
NETWORK Attack complexity
LOW Privileges required
NONE Confidentiality impact
NONE Integrity impact
NONE Availability impact
HIGH network
low complexity
cisco
nessus
Published: 2020-09-23
Updated: 2021-10-29
Summary
Multiple vulnerabilities in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality in Cisco IOS XR Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition. The vulnerabilities are due to incorrect processing of BGP update messages that contain crafted EVPN attributes. An attacker could exploit these vulnerabilities by sending BGP EVPN update messages with malformed attributes to be processed by an affected system. A successful exploit could allow the attacker to cause the BGP process to restart unexpectedly, resulting in a DoS condition. The Cisco implementation of BGP accepts incoming BGP traffic only from explicitly defined peers. To exploit these vulnerabilities, the malicious BGP update message would need to come from a configured, valid BGP peer, or would need to be injected by the attacker into the victim's BGP network on an existing, valid TCP connection to a BGP peer.
Vulnerable Configurations
| Part | Description | Count |
| OS | Cisco | 4 |
| Hardware | Cisco | 25 |
Nessus
| NASL family | CISCO |
| NASL id | CISCO-SA-20200122-IOS-XR-EVPN.NASL |
| description | According to its self-reported version, Cisco IOS XR Software is affected by multiple denial of service (DoS) vulnerabilities in the implementation of Border Gateway Protocol (BGP) Ethernet VPN (EVPN) functionality. These are due to incorrect processing of BGP update messages that contain crafted EVPN attributes. An unauthenticated, remote attacker can exploit these, by sending BGP EVPN update messages with malformed attributes to be processed by an affected system. A successful exploit allows the attacker to cause the BGP process to restart unexpectedly, resulting in a DoS condition. To exploit these vulnerabilities, the malicious BGP update message would need to come from a configured, valid BGP peer, or would need to be injected by the attacker into the victim |
| last seen | 2020-05-21 |
| modified | 2020-01-31 |
| plugin id | 133409 |
| published | 2020-01-31 |
| reporter | This script is Copyright (C) 2020 and is owned by Tenable, Inc. or an Affiliate thereof. |
| source | https://www.tenable.com/plugins/nessus/133409 |
| title | Cisco IOS XR Software BGP EVPN DoS (cisco-sa-20200122-ios-xr-evpn) |