Cisco IOS Denilal of Service (DoS) attack attempt

critical Nessus Network Monitor Plugin ID 700129
New! Plugin Severity Now Using CVSS v3

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The remote host is running a version of Cisco IOS that is being targeted by a Denial of Service attack vector.


Versions of Cisco a flaw that is triggered when handling Cluster Management Protocol-specific Telnet options while establishing a Telnet session on a device which accepts Telnet connections. This may allow a remote attacker to potentially execute arbitrary code or cause a DoS.


Disabling the Telnet protocol as an allowed protocol for incoming connections would eliminate the exploit vector. Disabling Telnet and using SSH is recommended by Cisco.

See Also

Plugin Details

Severity: Critical

ID: 700129

Family: Generic

Published: 6/6/2017

Updated: 3/6/2019

Nessus ID: 97991, 103783

Risk Information


Risk Factor: Critical

Base Score: 10

Temporal Score: 8.7

Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C

Temporal Vector: CVSS2#E:ND/RL:OF/RC:C


Risk Factor: Critical

Base Score: 9.8

Temporal Score: 9.4

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

Temporal Vector: CVSS:3.0/E:X/RL:O/RC:C

Vulnerability Information

CPE: cpe:2.3:o:cisco:ios:*:*:*:*:*:*:*:*

Patch Publication Date: 4/21/2017

Vulnerability Publication Date: 3/17/2017

Reference Information

CVE: CVE-2017-3881

BID: 96960