PT-2017-2018 · Cisco · Cisco Ios Xe+1

Published 2017-03-22 · Updated 2020-07-27 · CVE-2017-3857

Positive Technologies (AI Summary)

CVSS v2.0

7.8

High

Base vector

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

Name of the Vulnerable Software and Affected Versions Cisco IOS versions 12.0 through 12.4 and 15.0 through 15.6 Cisco IOS XE versions 3.1 through 3.18

Description A vulnerability in the Layer 2 Tunneling Protocol (L2TP) parsing function exists due to insufficient validation of L2TP packets. This could allow an unauthenticated, remote attacker to cause an affected device to reload, resulting in a denial of service (DoS) condition. The vulnerability can be exploited by sending a crafted L2TP packet to an affected device. The L2TP feature is not enabled by default, and the device must be configured as an L2TP Version 2 (L2TPv2) or L2TP Version 3 (L2TPv3) endpoint to be affected.

Recommendations For Cisco IOS versions 12.0 through 12.4 and 15.0 through 15.6, update to a fixed version of Cisco IOS. For Cisco IOS XE versions 3.1 through 3.18, update to a fixed version of Cisco IOS XE. As a temporary workaround, consider disabling the L2TP feature until a patch is available. Restrict access to the L2TP parsing function to minimize the risk of exploitation.

Fix

DoS

Resource Exhaustion

Weakness Enumeration

CWE-400

CWE-399

Related Identifiers

BDU:2017-01185

CVE-2017-3857

Affected Products

Cisco Ios

Cisco Ios Xe

References · 6

• https://bdu.fstec.ru/vul/2017-01185 · Security Note
• https://nvd.nist.gov/vuln/detail/CVE-2017-3857 · Security Note
• https://osv.dev/vulnerability/CVE-2017-3857 · Vendor Advisory
• http://securitytracker.com/id/1038100 · Note
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20170322-l2tp · Note
• http://securityfocus.com/bid/97010 · Note