CVE-2017-3881

CRITICAL9.8

CISA KEV

Published 2017-03-17 · Updated 2026-06-17 · Source psirt@cisco.com

Summary

CVE-2017-3881 is a critical-severity (CVSS 9.8) vulnerability in Cisco IOS and IOS XE. CISA added it to the Known Exploited Vulnerabilities catalog on March 25, 2022, which means exploitation in the wild has been confirmed; US federal agencies had to remediate it by April 15, 2022. CISA does not currently list it as used in ransomware campaigns. Cisco has 102 vulnerabilities in the KEV catalog, 7 of them linked to ransomware.

All 102 known-exploited Cisco vulnerabilities →

Description

A vulnerability in the Cisco Cluster Management Protocol (CMP) processing code in Cisco IOS and Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a reload of an affected device or remotely execute code with elevated privileges. The Cluster Management Protocol utilizes Telnet internally as a signaling and command protocol between cluster members. The vulnerability is due to the combination of two factors: (1) the failure to restrict the use of CMP-specific Telnet options only to internal, local communications between cluster members and instead accept and process such options over any Telnet connection to an affected device; and (2) the incorrect processing of malformed CMP-specific Telnet options. An attacker could exploit this vulnerability by sending malformed CMP-specific Telnet options while establishing a Telnet session with an affected Cisco device configured to accept Telnet connections. An exploit could allow an attacker to execute arbitrary code and obtain full control of the device or cause a reload of the affected device. This affects Catalyst switches, Embedded Service 2020 switches, Enhanced Layer 2 EtherSwitch Service Module, Enhanced Layer 2/3 EtherSwitch Service Module, Gigabit Ethernet Switch Module (CGESM) for HP, IE Industrial Ethernet switches, ME 4924-10GE switch, RF Gateway 10, and SM-X Layer 2/3 EtherSwitch Service Module. Cisco Bug IDs: CSCvd48893.

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

CWE-20CWE-20

CISA Known-Exploited Vulnerability

Product: Cisco — IOS and IOS XE

Name: Cisco IOS and IOS XE Remote Code Execution Vulnerability

Date added: 2022-03-25 · Due: 2022-04-15

Required action: Apply updates per vendor instructions.

References

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