{"id":"CVE-2009-2055","kind":"vulnerability","aliases":["CVE-2009-2055"],"related":[],"title":"Cisco IOS XR: Cisco IOS XR Border Gateway Protocol (BGP) Denial-of-Service Vulnerability","description":"Cisco IOS XR 3.4.0 through 3.8.1 allows remote attackers to cause a denial of service (session reset) via a BGP UPDATE message with an invalid attribute, as demonstrated in the wild on 17 August 2009.","summary":"Cisco IOS XR routers running BGP can be crashed or disrupted by a remote attacker sending crafted traffic. The attacker gets denial of service, not code execution or data access.","severity":"high","cvss":5.9,"epss":0.03314,"exploited":true,"exploited_at":"2022-03-25T00:00:00+00:00","products":[{"name":"Cisco IOS XR","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["bgp","cisco","exploited","infrastructure","ios-xr","network-operators"],"not_affected_if":["bgp-not-configured","non-ios-xr-platform"],"how_to_check":null,"fix":"Apply the Cisco IOS XR update per the vendor advisory (CISA required action: apply updates per vendor instructions); the fixed version is unknown from the sources.","status":"open","published_at":"2009-08-19T17:30:01+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:22:03+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:22:03Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Cisco IOS XR update per the vendor advisory (CISA required action: apply updates per vendor instructions); the fixed version is unknown from the sources.","reach":"network","impact":"low","summary":"Cisco IOS XR routers running BGP can be crashed or disrupted by a remote attacker sending crafted traffic. The attacker gets denial of service, not code execution or data access.","category":"infrastructure","who_cares":["cisco","ios-xr","bgp","network-operators"],"confidence":0.6,"needs_auth":"no","worst_case":"Remote attacker causes router denial of service, disrupting routing.","analyst_note":"Find the Cisco advisory for CVE-2009-2055 and the fixed IOS XR releases; confirm affected versions and whether a workaround exists for BGP.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["bgp-not-configured","non-ios-xr-platform"],"user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000469,"input_tokens":2841,"output_tokens":370,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2009':17A,20A '-2055':18A,21A '17':97C '2009':99C '3.4.0':68C '3.8.1':70C 'access':64B 'allow':71C 'attack':49B,54B,73C 'attribut':90C 'august':98C 'bgp':10A,25B,40B,84C 'border':7A 'caus':75C 'cisco':1A,4A,22A,26B,35B,65C 'code':60B 'craft':51B 'crash':43B 'cve':16A,19A 'data':63B 'demonstr':92C 'denial':12A,56B,77C 'denial-of-servic':11A 'disrupt':45B 'execut':61B 'exploit':27B 'gateway':8A 'get':55B 'infrastructur':28B 'invalid':89C 'io':2A,5A,30B,36B,66C 'ios':23A 'ios-xr':29B 'messag':86C 'network':33B 'network-oper':32B 'oper':34B 'protocol':9A 'remot':48B,72C 'reset':81C 'router':38B 'run':39B 'send':50B 'servic':14A,58B,79C 'session':80C 'traffic':52B 'updat':85C 'via':82C 'vulner':15A 'wild':95C 'xr':3A,6A,24A,31B,37B,67C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2009-08-19T17:30:01+00:00","kev":{"dateAdded":"2022-03-25","dueDate":"2022-04-15","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H","cvss_by":"134c704f-9b21-4f2e-91b3-4a467353bcc0","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2009-2055","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2009-2055","severity":null,"published_at":"2022-03-25T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T11:39:17+00:00","note":null},{"source":"epss","external_id":"CVE-2009-2055","url":"https://api.first.org/data/v1/epss?cve=CVE-2009-2055","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-2009-2055","url":"https://nvd.nist.gov/vuln/detail/CVE-2009-2055","severity":null,"published_at":"2009-08-19T17:30:01+00:00","modified_at":"2026-06-16T23:08:40+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"}