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Full vulnerability report · 2017
CVE-2017-12238High confidence

Cisco Catalyst 6800 Series Switches VPLS Denial-of-Service Vulnerability

Cisco · Catalyst 6800 Series Switches

Official source article: Cisco CISCO-SA-20170927-VPLS ↗. Check the applicable product and release in the original source.

6.5MediumCVSS 3.1
Recommended action
Protect now

CISA confirms exploitation in the wild and lists 2022-03-24 as the remediation due date.

Fix not verified
R
Operational reassessment

Published severity in operational context

Open reassessment dashboard →
Published severityMediumOperational priority:Critical, raised 2 bands.upgradedsince 3 Mar 2022

Evidence used

  • CISA confirms exploitation in the wild.
  • EPSS is 2.02% for the current model date.

Compensating controls

  • Restrict local access and enforce least privilege on affected hosts.
  • Increase monitoring for the attack path and post-exploitation behaviour described in the report.

Verification

  1. Confirm that the asset runs Cisco Catalyst 6800 Series Switches and falls inside the recorded affected range.
  2. Recheck the vendor advisory before scheduling a change because no verified fixed version is currently retained.
  3. Validate exposure, authentication requirements and compensating controls in the actual environment.
  4. Reopen this reassessment when CVSS, KEV, EPSS, exploit evidence or remediation changes.
Mitigation target: Within 3 daysRemediation target: Within 90 days

This automated reassessment organises public evidence. It does not know asset exposure, business impact or control effectiveness and does not replace CVSS or a human risk decision.

Optional official sources

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

Choose official national sources for this report. Each advisory shows its original language. Your selection is remembered on this device and included in shared links.

Official European source

ENISA European Vulnerability Database

Official EUVD identifiers, advisory evidence and known-exploited context. Missing fields are not treated as evidence of low risk.

1 current
ENISA EUVD identifier

EUVD-2017-3811

CISA KEV mirrored by ENISA

A vulnerability in the Virtual Private LAN Service (VPLS) code of Cisco IOS 15.0 through 15.4 for Cisco Catalyst 6800 Series Switches could allow an unauthenticated, adjacent attacker to cause a C6800-16P10G or C6800-16P10G-XL type line card to crash, resulting in a denial of service (DoS) condition. The vulnerability is due to a memory management issue in the affected software. An attacker could exploit this vulnerability by creating a large number of VPLS-generated MAC entries in the MAC address table of an affected device. A successful exploit could allow the attacker to cause a C6800-16P10G or C6800-16P10G-XL type line card to crash, resulting in a DoS condition. This vulnerability affects Cisco Catalyst 6800 Series Switches that are running a vulnerable release of Cisco IOS Software and have a Cisco C6800-16P10G or C6800-16P10G-XL line card in use with Supervisor Engine 6T. To be vulnerable, the device must also be configured with VPLS and the C6800-16P10G or C6800-16P10G-XL line card needs to be the core-facing MPLS interfaces. Cisco Bug IDs: CSCva61927.

EUVD state
Present in the current official mapping
Known exploitation
Recorded by ENISA since 3 Mar 2022. Evidence sources: cisa_kev.
ENISA score
6.5 · CVSS 3.1
Advisory evidence
1 linked advisory record
Recommended actionProtect now

CISA confirms exploitation in the wild and lists 2022-03-24 as the remediation due date.

Fix not verified
01

What, why and how

A vulnerability in the Virtual Private LAN Service (VPLS) code of Cisco IOS for Cisco Catalyst 6800 Series Switches could allow an unauthenticated, adjacent attacker to cause a denial of service.

What

A vulnerability in the Virtual Private LAN Service (VPLS) code of Cisco IOS for Cisco Catalyst 6800 Series Switches could allow an unauthenticated, adjacent attacker to cause a denial of service.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through the affected interface may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

What

A vulnerability in the Virtual Private LAN Service (VPLS) code of Cisco IOS for Cisco Catalyst 6800 Series Switches could allow an unauthenticated, adjacent attacker to cause a denial of service.

Why

The current structured CVE record identifies a security weakness, but the root cause requires confirmation in the linked vendor material.

How

An attacker operating through the affected interface may attempt exploitation without authentication or user interaction. If successful, the issue may disrupt the affected service.

02

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 2022-03-03.

Public PoC / exploit material
?Confirmed exploitation and public exploit material are separate signals. Attacks can occur without public proof-of-concept or exploit code.
None recorded

No exploit-tagged reference or CISA SSVC proof-of-concept state is currently recorded. Research may still exist outside the structured feeds.

Likely attack path
the affected interface → vulnerable operation → disrupt the affected service
Attack surface
Unspecified
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-399 ↗

CWE-399. Open the MITRE definition for the exact weakness description.

CVSS vector
?CVSS means Common Vulnerability Scoring System. The vector records the metric values used to calculate technical severity.
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Common Vulnerability Scoring System 3.1: the compact vector below is decoded into plain language.

AVAdjacentAttack vector: The attacker must be on an adjacent or logically close 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.CNoneConfidentiality impact: No direct loss is represented by this metric.INoneIntegrity impact: No direct loss is represented by this metric.AHighAvailability impact: A successful attack can cause a major loss.
Post-exploitation / living off the land
No specific living-off-the-land technique is confirmed in the structured sources. Monitor normal administration tools for activity inconsistent with the affected service's baseline.
UnauthenticatedDenial of serviceCWE-399CISA KEV
A

Official authority intelligence

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

ENISA EUVD · EUVD-2017-3811Known-exploited evidence recorded

A vulnerability in the Virtual Private LAN Service (VPLS) code of Cisco IOS 15.0 through 15.4 for Cisco Catalyst 6800 Series Switches could allow an unauthenticated, adjacent attacker to cause a C6800-16P10G or C6800-16P10G-XL type line card to crash, resulting in a denial of service (DoS) condition. The vulnerability is due to a memory management issue in the affected software. An attacker could exploit this vulnerability by creating a large number of VPLS-generated MAC entries in the MAC address table of an affected device. A successful exploit could allow the attacker to cause a C6800-16P10G or C6800-16P10G-XL type line card to crash, resulting in a DoS condition. This vulnerability affects Cisco Catalyst 6800 Series Switches that are running a vulnerable release of Cisco IOS Software and have a Cisco C6800-16P10G or C6800-16P10G-XL line card in use with Supervisor Engine 6T. To be vulnerable, the device must also be configured with VPLS and the C6800-16P10G or C6800-16P10G-XL line card needs to be the core-facing MPLS interfaces. Cisco Bug IDs: CSCva61927.

Official EUVD record ↗
Canadian Centre for Cyber Security · English · AV17-144Cisco security updates

Cisco released multiple security updates to address vulnerabilities in the following products. -Cisco IOS XE Software Web UI REST API Authentication Bypass Vulnerability -Cisco IOS XE Software Web UI Privilege Escalation Vulnerability -Cisco IOS and IOS XE Software DHCP Remote Code Execution Vulnerability -Cisco Mobility Express 1800 Access Point Series Authentication Bypass Vulnerability -Cisco IOS Software for Cisco Catalyst 6800 Series Switches VPLS Denial of Service Vulnerability -Cisco IOS Software for Cisco Integrated Services Routers Generation 2 Denial of Service Vulnerability -Cisco IOS Software for Cisco Industrial Ethernet Switches PROFINET Denial of Service Vulnerability -Cisco IOS and IOS XE Software Plug-and-Play PKI API Certificate Validation Vulnerability -Cisco IOS XE Software for Cisco 5760 WLC, Cisco Catalyst 4500E Supervisor Engine 8-E, and Cisco NGWC 3850 GUI Privilege Escalation Vulnerability -Cisco IOS Software Network Address Translation Denial of Service Vulnerability -Cisco IOS XE Software Locator/ID Separation Protocol Authentication Bypass Vulnerability -Cisco IOS XE Wireless Controller Manager Denial of Service Vulnerability -Cisco IOS and IOS XE Software Internet Key Exchange Denial of Service Vulnerability -Cisco IOS Software Common Industrial Protocol Request Denial of Service Vulnerabilities -Cisco IOS XE Software for Cisco ASR 1000 Series and cBR-8 Routers Line Card Console Access Vulnerability CVE References: CVE-2017-3831, CVE-2017-12222, CVE-2017-12226, CVE-2017-12228, CVE-2017-12229, CVE-2017-12230, CVE-2017-12231, CVE-2017-12232, CVE-2017-12233, CVE-2017-12234, CVE-2017-12235, CVE-2017-12236, CVE-2017-12237, CVE-2017-12238, CVE-2017-12239, CVE-2017-12240

Official advisory ↗
CERT-FR · French · CERTFR-2017-AVI-325Multiples vulnérabilités dans les produits Cisco

De multiples vulnérabilités ont été découvertes dans les produits Cisco. Certaines d'entre elles permettent à un attaquant de provoquer une exécution de code arbitraire à distance, un déni de service à distance et un contournement de la politique de sécurité.

Official advisory ↗
JVN iPedia · Japanese · JVNDB-2017-008507Cisco IOS におけるリソース管理に関する脆弱性

Cisco IOS には、リソース管理に関する脆弱性が存在します。 ベンダは、本脆弱性を Bug ID CSCva61927 として公開しています。

Official advisory ↗
KISA KrCERT/CC · Korean · KNVD-4783Cisco 제품군 취약점 보안 업데이트 권고

(CVE-2017-12238) [5]

Official advisory ↗
03

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: Cisco IOS
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. Limit untrusted access and use least privilege until authoritative guidance is available.
04

Evidence and provenance

Published 28 Sept 2017 · Last source change 12 Jan 2026, 21:46 UTC · CWE-399

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-2017-3811
Product sourceCISA KEV
Remediation sourceCVE/CNA references
CWE sourceCNA
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. 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-2017-3811)
    ENISA EUVD ↗
  2. ENISA EUVD mappingEUVD-2017-3811 was added to the official ENISA EUVD mapping for this CVE.
    Before
    not recorded
    After
    {"euvdId":"EUVD-2017-3811"}
    ENISA EUVD ↗
  3. Affected versionsThe structured affected or fixed version information changed.
    Before
    Cisco IOS · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    After
    Cisco IOS: Cisco IOS · Fixed: No fixed version is explicitly recorded in the structured CVE data.
    CNA ↗
  4. Vendor guidanceAuthoritative vendor guidance changed: added vendor advisory: tools.cisco.com/cisco-sa-20170927-vpls.
    Before
    no authoritative guidance recorded
    After
    vendor advisory: tools.cisco.com/cisco-sa-20170927-vpls
    tools.cisco.com ↗
  5. CVSS scoreCVSS scoring authority changed from CISA ADP to NIST NVD; the displayed base score remained 6.5.
    Before
    6.5 (CVSS 3.1 · CISA ADP · CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
    After
    6.5 (CVSS 3.1 · NIST NVD · CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
    NIST NVD ↗
  6. Catalogue recordCVE added to the BlackTree catalogue.
    CNA ↗
Material fields only · duplicate refreshes suppressed · history retained for the configured operational retention period
CVE published
Added to CISA KEV
ENISA EUVD · EUVD-2017-3811↗CISA KEV record↗Vendor advisory · Cisco CISCO-SA-20170927-VPLS↗CVE authority or vendor 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.
Free version - for non-commercial use only.CVE-2017-12238 · cve.blacktree.nl