vulnerability / NVI-00001479 / Revision 5
CVE-2017-3881
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.
This report has not inspected your inventory, configuration, deployed build, reachability or evidence. A catalog listing and a severity score do not establish exposure or compromise.
01 / Meaning
Why it matters
Published affected context helps an owner decide what evidence to gather. This report has not examined your application.
9.8 CRITICAL (3.1)
CISA-ADP severity and vector CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H; not a measure of customer compromise.
Listed
CISA lists known exploitation. This does not establish exploitation of your system.
As of · CISA
10 HIGH (2.0)
nvd@nist.gov severity; no combined Null risk score.
9.8 CRITICAL (3.1)
nvd@nist.gov severity; no combined Null risk score.
9.8 CRITICAL (3.1)
134c704f-9b21-4f2e-91b3-4a467353bcc0 severity; no combined Null risk score.
98.975%
FIRST EPSS model v2026.06.15; exploitation probability over 30 days, percentile 0.9993. Missing scores are unknown.
As of · FIRST EPSS
02 / Applicability
The affected context
Affected versions, configuration prerequisites and known exclusions are public. Confirm each one against the deployed service.
Cisco IOS and IOS XE Software
source listedCisco IOS and IOS XE Software
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 Laye
Cisco IOS and IOS XE
source listedThe linked source does not supply a complete affected-version range here.
CISA does not supply a complete application-specific affected range here. Follow the linked vendor advisory for version and configuration prerequisites.
03 / Response
What to do next
- investigate
Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. FIRST EPSS
- investigate
Apply updates per vendor instructions.
Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system. CISA
A fixed release is not deployment evidence.
Check current vendor support and compatibility. After making a change, verify the deployed build and relevant runtime conditions. Keep the evidence, owner and time. An updated lockfile alone does not prove what is running.
04 / Limits
What this report cannot establish
- Customer inventory, deployment, reachability and exploitation have not been inspected.
- CISA catalog date-added and due-date fields are not the original vulnerability disclosure date or universal legal deadlines.
- NVD lastModified does not establish freshness of every associated CPE record.
05 / Provenance
Sources you can inspect
Each assertion retains its source. Mirrored records may repeat one underlying publisher; additional links are not independent corroboration.
- CVE-2017-3881 ↗
CVE Program / attributed CNA and ADP · cna record
Observed . CVE content: copyright The MITRE Corporation; CVE Terms of Use and license apply. CNA and ADP publishers retain separate attribution.
- CVE-2017-3881 ↗
CISA · official catalog
Observed . CISA KEV; CC0 1.0. Catalog assertions are not evidence of customer compromise.
- CVE-2017-3881 ↗
NIST National Vulnerability Database · official catalog
Observed . This product uses data from the NVD API but is not endorsed or certified by the NVD.
- CVE-2017-3881 ↗
FIRST EPSS · official catalog
Observed . FIRST EPSS; probability of exploitation in the next 30 days, not local compromise. Dataset date/model retained; FIRST services terms apply.
Public revision history
Only published revisions appear here. Routine fetches do not create a material-change event.
- Revision 5 ·
Source facts changed; compare the preserved prior revision.
- Revision 4 ·
Dated EPSS estimate updated; this is not a new disclosure or proof of exploitation.
- Revision 3 ·
Source facts changed; compare the preserved prior revision.
- Revision 1 ·
First indexed by Null; source disclosure date is shown separately.