Vulnerability report

Exploited in the wild Confirmed confidence In CISA KEV

CVE-2017-3881

Cisco IOS and IOS XE Software

Cisco IOS and IOS XE Software · Cisco IOS and IOS XE Software

Watch CVE-2017-3881 Browse KEV feed
Severity
CVSS 9.8 · Critical
Confidence
Confirmed
Exploit status
Exploited in the wild
EPSS
99.0%
First observed
—
Last observed
—

Decision summary

What security teams need to know first

Direct answers before the deeper technical record.

What it is

CVE-2017-3881 is an unauthenticated vulnerability affecting Cisco 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...

Is it exploited?

Yes. Previdian tracks this CVE as a known exploited vulnerability. Confidence is confirmed. Listed in CISA KEV.

Who is affected?

Cisco IOS and IOS XE Software cisco ios and ios xe software.

What should we do?

Prioritize remediation. Validate affected assets and apply vendor fixes on an accelerated timeline.

Overview

Cisco 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 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.

n/a Affected
Cisco IOS and IOS XE Software
Cisco IOS and IOS XE Software
Published
17 Mar 2017
Exploitation Reported
25 Mar 2022
Attack vector
Remote
Complexity
Low
Privileges
None
User interaction
None

Tags

ios edge cisa nuclei_scanner

CVE References

  • CVE Record CVE.org · CVE Record https://www.cve.org/CVERecord?id=CVE-2017-3881
  • 41872 exploit-db.com · Exploit https://www.exploit-db.com/exploits/41872/
  • 41874 exploit-db.com · Exploit https://www.exploit-db.com/exploits/41874/
  • 97391 securityfocus.com · VDB Entry http://www.securityfocus.com/bid/97391
  • 96960 securityfocus.com · VDB Entry http://www.securityfocus.com/bid/96960
  • 1038059 securitytracker.com · VDB Entry http://www.securitytracker.com/id/1038059
  • tools.cisco.com/security/center/content/CiscoSecurityAdvisor... tools.cisco.com · CVE Record https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory...

Exploitation evidence

Why Previdian marks this CVE as exploited

Third-party attestation and first-party sensor observation are shown separately so teams can judge the evidence chain.

Exploited in the wild

CISA

Recorded 25 Mar 2022

A trusted third party reported exploitation.

Proof of concept available

GitHub

Recorded 20 Apr 2017

Public scanner or PoC coverage increases practical exploitability.

Known exploited vulnerability sources

Per-source evidence links for KEV attestations are available through the Previdian Pro API.

Learn about Pro API access
Source Added
CISA First 2022-03-25 00:00 UTC

Detection

Operational artifacts and observed signals

Make the evidence actionable in scanner, SOC, and edge-control workflows.

Observed signals

Request targets
User-Agents
Callback hosts
0
0
0

Request targets and User-Agents available in Pro. Callback host details available in Enterprise.

Virtual patch status

No Previdian virtual patch is currently available. Future rules ship for ModSecurity, Cloudflare, and AWS WAF.

Learn about virtual patches →

Scanner Artifacts

Scanner and exploit-framework references linked to this CVE.

Scanner Reference Detected
Nuclei https://github.com/projectdiscovery/nuclei-templates/blob/main/network/cves/2017/CVE-2017-3881.yaml 25 Apr 2025

Risk and context

Severity, weaknesses, and research context

CVSS v3.1

9.8 Critical

Potential damage if exploited. Separate from whether attackers are using it.

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

EPSS

99.0%

Estimated chance of exploitation in the next 30 days. Previdian's warning comes from evidence, not this score.

Weaknesses

Improper Input Validation CWE-20

All CVSS Scores

CVSS v3.1 9.8 Critical

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

CVSS v2.0 10.0 High

AV:N/AC:L/Au:N/C:C/I:C/A:C

Potential Proof of Concepts

These PoCs are unverified and could contain malware. Use at your own risk.

Cisco IOS 12.2(55)SE11 - Remote Code Execution

nuclei · Created Unknown

Timeline

From disclosure to observed exploitation

  1. 14:20 UTC

    Public PoC available

    Public proof-of-concept code published

  2. 00:00 UTC

    Nuclei template available

    Scanner coverage available

  3. 00:00 UTC

    Added to CISA KEV

    Listed in the CISA Known Exploited Vulnerabilities catalog

  4. 22:00 UTC

    CVE published

    Vulnerability disclosed publicly

  5. 00:00 UTC

    CVE ID reserved

    Identifier reserved by the CNA

Pro API

Automate this intelligence

Confidence, exploit status, sensor telemetry, PoCs, scanner integrations, mentions, and tags are available programmatically for VM, SOC, and CTI workflows.

Start 14-day Pro trial Read API docs
  • Evidence confidence and provenance
  • First-party sensor telemetry
  • PoC and scanner references
  • Affected versions and enrichment
  • Automation-ready JSON delivery

GET /api/v2/pro/kevs/CVE-2017-3881

Sample API response 
{
  "cve_id": "CVE-2017-3881",
  "confidence": "Confirmed",
  "cvss_score": 9.8,
  "cvss_estimated": false,
  "epss_score": 0.9895,
  "exploit_status": {
    "exploited_in_the_wild": true,
    "active_exploitation_observed": false
  },
  "sensor_telemetry": { "attempts": 0, "sensors": 0 }
}