New! CVE Severity Now Using CVSS v3

The calculated severity for CVEs has been updated to use CVSS v3 by default. CVEs that do not have a CVSS v3 score will fall back CVSS v2 for calculating severity. Severity display preferences can be toggled in the settings dropdown.


A vulnerability in the Layer 2 Tunneling Protocol (L2TP) parsing function of Cisco IOS (12.0 through 12.4 and 15.0 through 15.6) and Cisco IOS XE (3.1 through 3.18) could allow an unauthenticated, remote attacker to cause an affected device to reload. The vulnerability is due to insufficient validation of L2TP packets. An attacker could exploit this vulnerability by sending a crafted L2TP packet to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. This vulnerability affects Cisco devices that are running a vulnerable release of Cisco IOS or Cisco IOS XE Software if the L2TP feature is enabled for the device and the device is configured as an L2TP Version 2 (L2TPv2) or L2TP Version 3 (L2TPv3) endpoint. By default, the L2TP feature is not enabled. Cisco Bug IDs: CSCuy82078.



Source: MITRE

Published: 2017-03-22

Updated: 2020-07-27

Type: CWE-400

Risk Information


Base Score: 7.8

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

Impact Score: 6.9

Exploitability Score: 10

Severity: HIGH


Base Score: 7.5

Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Impact Score: 3.6

Exploitability Score: 3.9

Severity: HIGH

Vulnerable Software

Configuration 1


cpe:2.3:o:cisco:ios:*:*:*:*:*:*:*:* versions from 12.0 to 12.4 (inclusive)

cpe:2.3:o:cisco:ios:*:*:*:*:*:*:*:* versions from 15.0 to 15.6 (inclusive)

cpe:2.3:o:cisco:ios_xe:*:*:*:*:*:*:*:* versions from 3.1.0 to 3.18.0 (inclusive)

Tenable Plugins

View all (2 total)

99029Cisco IOS XE L2TP Parsing DoS (cisco-sa-20170322-l2tp)NessusCISCO
99028Cisco IOS L2TP Parsing DoS (cisco-sa-20170322-l2tp)NessusCISCO