A vulnerability in the Border Gateway Patrol (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.

References

• https://nvd.nist.gov/vuln/detail/CVE-2019-1849
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20190515-iosxr-evpn-dos
• http://www.securityfocus.com/bid/108342