{"id":"CVE-2017-12238","kind":"vulnerability","aliases":["CVE-2017-12238"],"related":[],"title":"Cisco Catalyst 6800 Series Switches: Cisco Catalyst 6800 Series Switches VPLS Denial-of-Service Vulnerability","description":"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.","summary":"A flaw in the VPLS code of Cisco IOS on Catalyst 6800 Series switches lets an unauthenticated attacker on an adjacent network segment crash or disrupt the switch. The attacker gets denial of service only, not code execution or data access, and CISA lists it as known exploited.","severity":"medium","cvss":6.5,"epss":0.02017,"exploited":true,"exploited_at":"2022-03-03T00:00:00+00:00","products":[{"name":"Cisco Catalyst 6800 Series Switches","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["catalyst-6800","cisco","exploited","infrastructure","network-operators"],"not_affected_if":["default-config","no-vpls-configured"],"how_to_check":null,"fix":"Apply the updates per Cisco's vendor instructions; the specific fixed IOS version is not stated in the sources.","status":"open","published_at":"2017-09-29T01:34:48+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:24:08+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:24:08Z","model":"claude-haiku-5-5","output":{"fix":"Apply the updates per Cisco's vendor instructions; the specific fixed IOS version is not stated in the sources.","reach":"network","impact":"low","summary":"A flaw in the VPLS code of Cisco IOS on Catalyst 6800 Series switches lets an unauthenticated attacker on an adjacent network segment crash or disrupt the switch. The attacker gets denial of service only, not code execution or data access, and CISA lists it as known exploited.","category":"infrastructure","who_cares":["cisco","catalyst-6800","network-operators"],"confidence":0.6,"needs_auth":"no","worst_case":"Switch stops forwarding traffic due to denial of service","analyst_note":"Confirm affected IOS versions and fixed release, and whether VPLS must be configured, at the Cisco advisory for CVE-2017-12238 and the CISA KEV entry.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["no-vpls-configured","default-config"],"user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"unknown"},"cost_usd":0.000482,"input_tokens":2892,"output_tokens":386,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-12238':19A,22A '-2017':18A,21A '-6800':29B '15.0':97C '15.4':99C '16p10g':117C,121C,187C,191C,227C,231C,256C,260C '6800':3A,8A,25A,47B,103C,208C '6t':240C 'access':76B 'address':169C 'adjac':56B,110C 'affect':147C,173C,205C 'allow':107C,179C 'also':247C 'attack':53B,65B,111C,150C,181C 'bug':274C 'c6800':116C,120C,186C,190C,226C,230C,255C,259C 'c6800-16p10g':115C,185C,225C,254C 'c6800-16p10g-xl':119C,189C,229C,258C 'card':125C,195C,234C,263C 'catalyst':2A,7A,24A,28B,46B,102C,207C 'caus':113C,183C 'cisa':78B 'cisco':1A,6A,23A,30B,43B,95C,101C,206C,218C,224C,273C 'code':41B,72B,93C 'condit':135C,202C 'configur':249C 'core':269C 'core-fac':268C 'could':106C,151C,178C 'crash':59B,127C,197C 'creat':156C 'cscva61927':276C 'cve':17A,20A 'data':75B 'denial':13A,67B,131C 'denial-of-servic':12A 'devic':174C,245C 'disrupt':61B 'dos':134C,201C 'due':139C 'engin':239C 'entri':165C 'execut':73B 'exploit':31B,83B,152C,177C 'face':270C 'flaw':37B 'generat':163C 'get':66B 'id':275C 'infrastructur':32B 'interfac':272C 'io':44B,96C,219C 'issu':144C 'known':82B 'lan':90C 'larg':158C 'let':50B 'line':124C,194C,233C,262C 'list':79B 'mac':164C,168C 'manag':143C 'memori':142C 'mpls':271C 'must':246C 'need':264C 'network':34B,57B 'network-oper':33B 'number':159C 'oper':35B 'privat':89C 'releas':216C 'result':128C,198C 'run':213C 'segment':58B 'seri':4A,9A,48B,104C,209C 'series':26A 'servic':15A,69B,91C,133C 'softwar':148C,220C 'success':176C 'supervisor':238C 'switch':5A,10A,49B,63B,105C,210C 'switches':27A 'tabl':170C 'type':123C,193C 'unauthent':52B,109C 'use':236C 'virtual':88C 'vpls':11A,40B,92C,162C,251C 'vpls-gener':161C 'vulner':16A,85C,137C,154C,204C,215C,243C 'xl':122C,192C,232C,261C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2017-09-29T01:34:48+00:00","kev":{"dateAdded":"2022-03-03","dueDate":"2022-03-24","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2017-12238","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2017-12238","severity":null,"published_at":"2022-03-03T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T10:39:07+00:00","note":null},{"source":"epss","external_id":"CVE-2017-12238","url":"https://api.first.org/data/v1/epss?cve=CVE-2017-12238","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:44+00:00","fetched_at":"2026-10-23T19:13:44+00:00","note":null},{"source":"nvd","external_id":"CVE-2017-12238","url":"https://nvd.nist.gov/vuln/detail/CVE-2017-12238","severity":null,"published_at":"2017-09-29T01:34:48+00:00","modified_at":"2026-06-17T01:02:56+00:00","first_seen_at":"2026-10-23T21:57:35+00:00","fetched_at":"2026-10-23T21:57:35+00:00","note":null}],"documents":[],"notice":"Free to read at a human pace. An API with keys and an MCP server are in preparation; early access: hello@infrastack.ai"}