PT-2017-4193 · Cisco · Cisco Ios Xe

Published

2017-11-03

·

Updated

2025-10-28

·

CVE-2017-12319

CVSS v2.0

7.8

High

VectorAV:N/AC:L/Au:N/C:N/I:N/A:C
Name of the Vulnerable Software and Affected Versions Cisco IOS XE Software versions prior to 16.3
Description A vulnerability in the Border Gateway Protocol (BGP) over an Ethernet Virtual Private Network (EVPN) for Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause the device to reload, resulting in a denial of service (DoS) condition, or potentially corrupt the BGP routing table, which could result in network instability. The vulnerability exists due to changes in the implementation of the BGP MPLS-Based Ethernet VPN RFC (RFC 7432) draft between IOS XE software releases. When the BGP Inclusive Multicast Ethernet Tag Route or BGP EVPN MAC/IP Advertisement Route update packet is received, it could be possible that the IP address length field is miscalculated. An attacker could exploit this vulnerability by sending a crafted BGP packet to an affected device after the BGP session was established. The vulnerability may be triggered when the router receives a crafted BGP message from a peer on an existing BGP session.
Recommendations For Cisco IOS XE Software versions prior to 16.3, update to software release 16.3 or later to resolve the issue. As a temporary workaround, consider restricting access to the BGP protocol to minimize the risk of exploitation. Avoid establishing BGP sessions with untrusted peers, and ensure that all BGP neighbors are explicitly defined and trusted.

Fix

DoS

RCE

Weakness Enumeration

Related Identifiers

BDU:2022-04009
CVE-2017-12319

Affected Products

Cisco Ios Xe