Cisco IOS L2TP Parsing DoS (cisco-sa-20170322-l2tp)

high Nessus Plugin ID 99028
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Synopsis

The remote device is missing a vendor-supplied security patch.

Description

According to its self-reported version, the Cisco IOS software running on the remote device is affected by a denial of service vulnerability in its Layer 2 Tunneling Protocol (L2TP) parsing function due to insufficient validation of L2TP packets. An unauthenticated, remote attacker can exploit this issue, via a specially crafted L2TP packet, to cause the device to reload.

Note that this issue only affects devices if the L2TP feature is enabled 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.

Solution

Upgrade to the relevant fixed version referenced in Cisco bug ID CSCuy82078.

See Also

http://www.nessus.org/u?d4fc7ea8

https://bst.cloudapps.cisco.com/bugsearch/bug/CSCuy82078

Plugin Details

Severity: High

ID: 99028

File Name: cisco-sa-20170322-l2tp-ios.nasl

Version: 1.9

Type: combined

Family: CISCO

Published: 3/28/2017

Updated: 11/13/2019

Dependencies: cisco_ios_version.nasl

Risk Information

CVSS Score Source: CVE-2017-3857

VPR

Risk Factor: Low

Score: 3.6

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 5.8

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

Temporal Vector: E:U/RL:OF/RC:C

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

Vector: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Temporal Vector: E:U/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:cisco:ios

Required KB Items: Host/Cisco/IOS/Version

Exploit Ease: No known exploits are available

Patch Publication Date: 3/22/2017

Vulnerability Publication Date: 3/22/2017

Reference Information

CVE: CVE-2017-3857

BID: 97010

CISCO-BUG-ID: CSCuy82078

CISCO-SA: cisco-sa-20170322-l2tp