CVE-2017-3881 / Cisco CISCO-SA-20170317-CMP: Cisco IOS and IOS XE Remote Code Execution Vulnerability

Recommended actionProtect now

CISA confirms exploitation in the wild and lists 2022-04-15 as the remediation due date.

Fix not verified

What, why and how

What

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

An attacker operating through a network path may attempt exploitation without authentication or user interaction. If successful, the issue may execute code or commands in the affected security context.

What

Why

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

How

Exploit reality and attack path

CVSS severity, EPSS forecast probability, public exploit material and CISA-confirmed exploitation are separate signals.

Observed exploitation

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

Confirmed in the wild

CISA added this CVE to its Known Exploited Vulnerabilities catalogue on 2022-03-25.

Public PoC / exploit material

Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.

Reference recorded

A structured CVE source labels at least one public reference as exploit material. BlackTree has not independently validated that it is safe, reliable or weaponised.

Likely attack path: a network path → Improper Input Validation → execute code or commands in the affected security context
Attack surface: Network
Privileges required: None: unauthenticated exploitation is possible
User interaction: None
Attack complexity: Low: no specialised conditions are recorded
Security boundary: Unchanged: impact remains within the vulnerable component's security authority
Weakness ? CWE means Common Weakness Enumeration: a standard category for the underlying weakness.: CWE-20 ↗
CWE-20: Improper Input Validation. The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.
CVSS vector ? CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.
AVNetworkAttack vector: The vulnerable component can be reached over a network.ACLowAttack complexity: No specialised conditions are required beyond attacker-controlled input.PRNonePrivileges required: The attacker does not need an account or existing privileges.UINoneUser interaction: No action by another user is required.SUnchangedScope: The security impact remains within the vulnerable component's authority.CHighConfidentiality impact: A successful attack can cause a major loss.IHighIntegrity impact: A successful attack can cause a major loss.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land: After compromise, an attacker may use built-in shells, scripting engines, scheduled tasks and native network utilities for discovery, persistence or movement. This is a plausible LoTL path, not evidence that it has occurred for every attack.

NetworkUnauthenticatedRemote code executionPrivilege escalationCWE-20CISA KEVPublic exploit reference

Official authority intelligence

Only matched European and national findings are included. Language selectors and unavailable sources are omitted.

ENISA EUVD · EUVD-2017-12998Known-exploited evidence recorded

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.

Official EUVD record ↗

Canadian Centre for Cyber Security · English · AV17-066Cisco security advisory

Cisco has released a Security Advisory to address a critical vulnerability in its Cluster Management Protocol (CMP) processing code which exists in Cisco IOS and Cisco IOS XE Software. Exploitation could allow a remote unauthenticated attacker to execute code and gain full control of an affected device. A full list of affected devices can be found in Cisco’s Security Advisory. CVE Reference: CVE-2017-3881

Official advisory ↗

Canadian Centre for Cyber Security · English · AL17-002Cisco IOS and IOS XE Software Cluster Management Protocol Vulnerability

CCIRC is aware of a recently disclosed vulnerability in Cisco’s IOS and IOS XE Software CMP. Identified as CVE-2017-3881, this vulnerability code can allow a remote unauthenticated attacker to cause a reload of the affected system or to remotely execute code. The vulnerability could be successfully exploited by sending malformed CMP-specific Telnet options while establishing a Telnet session with a CISCO device configured to accept Telnet connections. There are over 300 models of Cisco switches that may be affected by this vulnerability. For an extensive list of devices please visit the vendor’s Advisory (listed below).

Official advisory ↗

CERT-FR · French · CERTFR-2017-AVI-143Vulnérabilité dans les commutateurs Cisco

Une vulnérabilité a été corrigée dans les commutateurs Cisco . Elle permet à un attaquant de provoquer une exécution de code arbitraire à distance.

Official advisory ↗

JVN iPedia · Japanese · JVNDB-2017-002736Cisco IOS および Cisco IOS XE の Cisco Cluster Management Protocol 処理コードにおける入力確認に関する脆弱性

Cisco IOS および Cisco IOS XE の Cisco Cluster Management Protocol (CMP) 処理コードには、入力確認に関する脆弱性が存在します。ベンダは、本脆弱性を Bug ID CSCvd48893 として公開しています。

Official advisory ↗

KISA KrCERT/CC · Korean · KNVD-4727Cisco IOS 소프트웨어 원격 코드 실행 취약점 보안 업데이트 권고

o Cisco社는 자사의 제품에 영향을 주는 취약점을 해결한 보안 업데이트를 발표 o 최근 해당 취약점을 악용한 공격이 발생하고 있어 최신버전으로 업데이트 권고 ##### □ 내용 o Cisco 제품의 Cluster Management Protocol(CMP)에서 잘못된 텔넷 옵션 처리로 인해 발생하는 원격 코드 실행 취약점 (CVE-2017-3881) [1]

Official advisory ↗

KISA KrCERT/CC · Korean · KNVD-4713Cisco IOS 소프트웨어 원격 코드 실행 취약점 주의 권고

o Cisco社는 자사의 제품에 영향을 주는 취약점을 공개 [1] o 공격자는 해당 취약점을 악용하여 원격 코드 실행 등의 피해를 발생시킬 수 있으므로 대응 방안에 따른 조치 권고 ##### □ 내용 o Cisco 제품의 Cluster Management Protocol(CMP)에서 잘못된 텔넷 옵션 처리로 인해 발생하는 원격 코드 실행 취약점 (CVE-2017-3881)

Official advisory ↗

Patch and workaround

Operational remediation based on structured source evidence.

Status ? Patch availability is based on structured fixed-version fields and authoritative update references. If no fix is verified, check the vendor advisory before making a change.: Fix not verified
Affected: Cisco IOS and IOS XE Software: Cisco IOS and IOS XE Software
Fixed: No fixed version is explicitly recorded in the structured CVE data.
Action: No verified patch reference is present in the current structured sources. Check the vendor advisory before making a change.
Workaround: No verified workaround is recorded. If business-safe, reduce exposure to the affected interface and allow only trusted sources until authoritative guidance is available.

Evidence and provenance

Published 17 Mar 2017 · Last source change 12 Jan 2026, 20:45 UTC · CWE-20 · Improper Input Validation

CVE recordCVE.org · 5.2

CVSS sourceNIST NVD

EPSS source

The date BlackTree first stored a score for this CVE from the daily FIRST EPSS feed.

FIRST · tracked since 2026-09-01

European sourceENISA EUVD · EUVD-2017-12998

Product sourceCISA KEV

Remediation sourceCVE/CNA references

CWE sourceCISA ADP

NVD statusNVD enriched

Core structured fields are present and their contributing authorities are shown above.

Material change intelligence

What changed after publication

View recent updates ↗

1 Sep 2026, 02:45 UTC
ENISA known-exploited stateENISA EUVD now records this CVE in its known-exploited dataset.
Before
not listed in ENISA EUVD known-exploited dataset
After
listed in ENISA EUVD known-exploited dataset (EUVD-2017-12998)
ENISA EUVD ↗
1 Sep 2026, 02:42 UTC
ENISA EUVD mappingEUVD-2017-12998 was added to the official ENISA EUVD mapping for this CVE.
Before
not recorded
After
{"euvdId":"EUVD-2017-12998"}
ENISA EUVD ↗
12 Jan 2026, 20:45 UTC
Affected versionsThe structured affected or fixed version information changed.
Before
Cisco IOS and IOS XE Software · Fixed: No fixed version is explicitly recorded in the structured CVE data.
After
Cisco IOS and IOS XE Software: Cisco IOS and IOS XE Software · Fixed: No fixed version is explicitly recorded in the structured CVE data.
CNA ↗
12 Jan 2026, 20:45 UTC
Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: tools.cisco.com/cisco-sa-20170317-cmp.
Before
no authoritative guidance recorded
After
vendor advisory: tools.cisco.com/cisco-sa-20170317-cmp
tools.cisco.com ↗
12 Jan 2026, 20:45 UTC
CVSS scoreCVSS scoring authority changed from CISA ADP to NIST NVD; the displayed base score remained 9.8.
Before
9.8 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
After
9.8 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H)
NIST NVD ↗
12 Jan 2026, 20:45 UTC
Catalogue recordCVE added to the BlackTree catalogue.
CNA ↗

2017-03-17CVE published

2022-03-25Added to CISA KEV

ENISA EUVD · EUVD-2017-12998↗CISA KEV record↗Vendor advisory · Cisco CISCO-SA-20170317-CMP↗Public exploit reference↗Official CVE record (CNA and ADP data)↗NVD record↗

Technical terms and abbreviations used in this report

CVE: Common Vulnerabilities and Exposures: the public identifier for one disclosed vulnerability.
CVSS: Common Vulnerability Scoring System: a technical severity framework; it is not patching priority by itself.
EPSS: Exploit Prediction Scoring System: FIRST's estimate of the probability that exploitation activity will be observed in the next 30 days; it is a forecast, not confirmation.
CWE: Common Weakness Enumeration: the standard category describing the underlying software or hardware weakness.
CNA: CVE Numbering Authority: an organisation authorised to assign and publish CVE records.
CISA ADP: Cybersecurity and Infrastructure Security Agency Authorized Data Publisher: structured enrichment added to a CVE record.
NVD: National Vulnerability Database: NIST's enrichment service for CVE records.
CERT / CSIRT: A computer security incident response team that publishes warnings or coordinates incident response.
PoC: Proof of concept: public material that demonstrates or helps reproduce exploitation.
CSAF: Common Security Advisory Framework: a machine-readable format for security advisories.
LoTL: Living off the land: abuse of legitimate tools or system functions during an attack.

Cisco IOS and IOS XE Remote Code Execution Vulnerability

Published severity in operational context

Evidence used

Compensating controls

Verification

National CERT insights
?
CERT means Computer Emergency Response Team; CSIRT is the closely related term Computer Security Incident Response Team.

ENISA European Vulnerability Database

EUVD-2017-12998

What, why and how

Exploit reality and attack path

Official authority intelligence

Patch and workaround

Evidence and provenance

What changed after publication