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[ CVE-2017-3881 · Published 17 Mar 2017 ]

Cisco IOS and IOS XE Remote Code Execution Vulnerability

Exploited · CISA KEV CVSS 9.8 EPSS 99%No fix listed yet

[ Why it matters ]Priority signals

  • Exploited in the wild: on CISA's Known Exploited Vulnerabilities list since 2022-03-25
  • EPSS: 99% chance of exploitation in the next 30 days (higher than 100% of CVEs)
  • Critical severity: CVSS 9.8

[ Description ]Official 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.

CISA: 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.

[ Fixes ]Fixes and patches

CISA required action (US federal deadline 15 Apr 2022): Apply updates per vendor instructions.

No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.

[ References ]References