Cisco · IOS and IOS XE
CVE-2017-3881
Cisco IOS and IOS XE Remote Code Execution Vulnerability
What it is
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.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: April 15, 2022
- Added to the CISA list
- March 25, 2022
- Published
- March 17, 2017
- Severity
- Critical 9.8 CVSS 3.1
- Chance of attacks in the next 30 days (EPSS)
- 99% in the top 0.1% of all known vulnerabilities
- Weakness
- CWE-20
- More details
- NVD · CVE.org · CISA
All references (6)
More exploited flaws from Cisco
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| Sep 29, 2025 | Software SNMP Denial of Service and Remote Code Execution | IOS and IOS XE | High 7.7 | 42% |
| Oct 10, 2023 | Group Encrypted Transport VPN Out-of-Bounds Write | IOS and IOS XE | Medium 6.6 | 2.5% |
| Nov 3, 2021 | Software Smart Install Remote Code Execution | IOS and IOS XE | High 7.5 | 99.5% |
| Oct 14, 2026 | Relative Path Traversal | Secure Email Gateway | Critical 9.8 | 2.2% |
| Sep 30, 2026 | Hex Encoding | Catalyst SD-WAN Manager | Critical 9.8 | 39% |
| Sep 16, 2026 | Incorrect Use of Privileged APIs | Identity Services Engine | Critical 10.0 | 76% |
| Sep 14, 2026 | SQL Injection | Secure Email Gateway | Critical 9.8 | 30% |
| Sep 9, 2026 | Firewall Management Center Authentication Bypass Using an Alternate Path or Channel | Secure Firewall Management Center (FMC) and Security Cloud Control (SCC) Firewall Management | Critical 10.0 | 88% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.