Vulnerabilities
CVE-2017-12238 — Cisco Catalyst 6800 Series Switches VPLS Denial-of-Service Vulnerability
CVE-2017-12238 · Cisco IOS · CVSS 6.5 · KEV
In brief
- Severity · CVSS
- Medium6.5CVSS 3.1, Medium
- EPSS
- 2%
- CISA KEV
- Known exploited, listed since 3 Mar 2022
- CERT-FR
- No advisory or alert referenced in the catalog
- Vendor
- Cisco
- Published · Modified
- ·
- Last verified
Summary
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.
Weakness: CWE-399
Title, description and the vendor's statements are quoted from the CVE record; a vendor's advisory is summarised in Patcharo's words, with a link.
Affected and fixed versions
Per product and release branch, as the vendor's CVE record and official advisory state them. A fixed release is shown only when a document names it: the vendor's, or CERT-FR's for Check Point, with its source.
Cisco IOS
- —Affected versionsCisco IOSFirst fixed releaseNot published in the sources followed
The vendor states fixes are available; the releases per branch are in its advisory.
Remediation
Fix available
Vendor fix
Cisco has released updates that fix this vulnerability; its advisory lists them.
SourceCisco Security Advisory cisco-sa-20170927-vpls· revised 27 Sept 2017
Workarounds (vendor)
Cisco states in its advisory that no workaround is available.
Last verified 1 Oct 2026 at 09:31 UTC
Known exploitation
Added to CISA KEV on 3 Mar 2022
Federal remediation due date: 24 Mar 2022
2% probability of exploitation in the next 30 days (percentile 80%).
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
CERT-FR
No CERT-FR advisory or alert of the last two years references this CVE, for the vendors Patcharo covers.
Timeline
- Published by the source
- Added to CISA KEV
- CISA remediation due date
- Source record last modified
- EPSS score computed
- Last verified by Patcharo
Official sources
- Cisco (CVE record)retrieved 1 Oct 2026 at 09:31 UTC
- CISA Known Exploited Vulnerabilitiesretrieved 1 Oct 2026 at 09:28 UTC
- NVDretrieved 27 Sept 2026 at 23:44 UTC
- FIRST EPSSretrieved 30 Sept 2026 at 00:17 UTC
- Cisco Security Advisory cisco-sa-20170927-vplsretrieved 1 Oct 2026 at 09:31 UTC
Vendor advisory
Cisco · CISA Known Exploited Vulnerabilities · NVD · FIRST EPSS · Cisco Security Advisory cisco-sa-20170927-vpls
How Patcharo reads this
Affected and fixed releases come from the vendor's structured statements and are matched against exact versions; CVSS from NVD, exploitation from CISA KEV and the vendor's own advisory, probability from FIRST EPSS. Missing data stays Unknown and never becomes Not affected.
Read the methodologyRead the guide: Cisco Secure Firewall release trains: Threat Defense, Management Center and ASA versions explained