{"id":"CVE-2023-29552","kind":"vulnerability","aliases":["CVE-2023-29552"],"related":[],"title":"The Service Location Protocol (SLP, RFC 2608) allows an unauthenticated, remote attacker to register arbitrary services","description":"The Service Location Protocol (SLP) contains a denial-of-service (DoS) vulnerability that could allow an unauthenticated, remote attacker to register services and use spoofed UDP traffic to conduct a denial-of-service (DoS) attack with a significant amplification factor.\n\nCISA required action: Apply mitigations per vendor instructions or disable SLP service or port 427/UDP on all systems running on untrusted networks, including those directly connected to the Internet.","summary":"The IETF Service Location Protocol (SLP) lets an unauthenticated remote attacker register services and abuse spoofed UDP traffic to run a denial-of-service attack with a large amplification factor. Attackers can use exposed SLP hosts to flood a victim with much more traffic than they send.","severity":"high","cvss":7.5,"epss":null,"exploited":true,"exploited_at":"2023-11-08T00:00:00+00:00","products":[{"name":"IETF Service Location Protocol (SLP)","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"netapp smi-s provider","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"suse manager server","fixed":[],"affected":"","ecosystem":"vendor"},{"name":"suse linux enterprise server","fixed":[],"affected":"= 11","ecosystem":"vendor"},{"name":"suse linux enterprise server","fixed":[],"affected":"= 12","ecosystem":"vendor"},{"name":"suse linux enterprise server","fixed":[],"affected":"= 15","ecosystem":"vendor"},{"name":"vmware esxi","fixed":["7.0"],"affected":"< 7.0","ecosystem":"vendor"},{"name":"service location protocol project service location protocol","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","infrastructure","internet-facing-hosts","slp","udp-427"],"not_affected_if":["internal-only-networks","port-427-blocked-from-untrusted-networks","slp-not-installed"],"how_to_check":"Check whether SLP is running and listening on UDP port 427 (for example: ss -lunp | grep 427 on Linux).\nCheck whether port 427/UDP is reachable from untrusted networks, including the internet.","fix":"Disable the SLP service or block port 427/UDP on systems on untrusted networks, per CISA's required action.\nApply the vendor mitigations for your SLP implementation; the sources do not name a fixed version.","status":"open","published_at":"2023-04-25T16:15:09+00:00","first_seen_at":"2026-10-23T19:11:51+00:00","triaged_at":"2026-10-23T21:02:57+00:00","updated_at":"2026-10-23T22:29:04+00:00","category":"infrastructure","confidence":0.6,"triage":{"at":"2026-10-23T21:02:57Z","model":"claude-haiku-5-5","output":{"fix":"Disable the SLP service or block port 427/UDP on systems on untrusted networks, per CISA's required action.\nApply the vendor mitigations for your SLP implementation; the sources do not name a fixed version.","reach":"internet","impact":"medium","summary":"The IETF Service Location Protocol (SLP) lets an unauthenticated remote attacker register services and abuse spoofed UDP traffic to run a denial-of-service attack with a large amplification factor. Attackers can use exposed SLP hosts to flood a victim with much more traffic than they send.","category":"infrastructure","who_cares":["slp","udp-427","internet-facing-hosts"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker turns exposed SLP hosts into amplified UDP flood against a victim.","analyst_note":"Find the vendor advisory and affected/fixed versions for the specific SLP implementation; the sources only give the CISA KEV entry and do not name products or versions.","how_to_check":"Check whether SLP is running and listening on UDP port 427 (for example: ss -lunp | grep 427 on Linux).\nCheck whether port 427/UDP is reachable from untrusted networks, including the internet.\nunknown","needs_analyst":true,"not_affected_if":["slp-not-installed","port-427-blocked-from-untrusted-networks","internal-only-networks"],"user_interaction":"no","needs_special_setup":"yes","severity_if_unknown":"high"},"cost_usd":0.000547,"input_tokens":2892,"output_tokens":516,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2023':18A,21A '-29552':19A,22A '-427':65B '2608':7A '427/udp':170C 'abus':80B 'action':158C 'allow':8A,129C 'amplif':95B,154C 'appli':159C 'arbitrari':15A 'attack':12A,76B,91B,97B,133C,150C 'cisa':156C 'conduct':143C 'connect':181C 'contain':119C 'could':128C 'cve':17A,20A 'denial':88B,122C,146C 'denial-of-servic':87B,121C,145C 'direct':180C 'disabl':165C 'dos':125C,149C 'enterprise':38A,42A,46A 'esxi':49A 'exploit':57B 'expos':100B 'face':61B 'factor':96B,155C 'flood':104B 'host':62B,102B 'ietf':23A,67B 'includ':178C 'infrastructur':58B 'instruct':163C 'internet':60B,184C 'internet-facing-host':59B 'larg':94B 'let':72B 'linux':37A,41A,45A 'locat':3A,69B,116C 'location':25A,51A,55A 'manager':34A 'mitig':160C 'much':108B 'netapp':28A 'network':177C 'per':161C 'port':169C 'project':53A 'protocol':4A,26A,52A,56A,70B,117C 'provider':32A 'regist':14A,77B,135C 'remot':11A,75B,132C 'requir':157C 'rfc':6A 'run':85B,174C 's':31A 'send':113B 'server':35A,39A,43A,47A 'servic':2A,16A,68B,78B,90B,115C,124C,136C,148C,167C 'service':24A,50A,54A 'signific':153C 'slp':5A,27A,63B,71B,101B,118C,166C 'smi':30A 'smi-s':29A 'spoof':81B,139C 'suse':33A,36A,40A,44A 'system':173C 'traffic':83B,110B,141C 'udp':64B,82B,140C 'unauthent':10A,74B,131C 'untrust':176C 'use':99B,138C 'vendor':162C 'victim':106B 'vmware':48A 'vulner':126C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2023-04-25T16:15:09+00:00","kev":{"dateAdded":"2023-11-08","dueDate":"2023-11-29","requiredAction":"Apply mitigations per vendor instructions or disable SLP service or port 427/UDP on all systems running on untrusted networks, including those directly connected to the Internet.","knownRansomwareCampaignUse":"Unknown"},"cvss_vector":"CVSS:3.1/AV:N/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-2023-29552","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2023-29552","severity":null,"published_at":"2023-11-08T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:51+00:00","fetched_at":"2026-10-25T11:39:15+00:00","note":null},{"source":"nvd","external_id":"CVE-2023-29552","url":"https://nvd.nist.gov/vuln/detail/CVE-2023-29552","severity":null,"published_at":"2023-04-25T16:15:09+00:00","modified_at":"2026-06-17T05:50:32+00:00","first_seen_at":"2026-10-23T22:29:04+00:00","fetched_at":"2026-10-23T22:29:04+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"}