{"id":"CVE-2018-20753","kind":"vulnerability","aliases":["CVE-2018-20753"],"related":[],"title":"Kaseya Virtual System/Server Administrator (VSA): Kaseya VSA Remote Code Execution Vulnerability","description":"Kaseya VSA RMM before R9.3 9.3.0.35, R9.4 before 9.4.0.36, and R9.5 before 9.5.0.5 allows unprivileged remote attackers to execute PowerShell payloads on all managed devices. In January 2018, attackers actively exploited this vulnerability in the wild.","summary":"Kaseya VSA, a remote monitoring and management server, has a flaw that lets unauthenticated remote attackers run PowerShell payloads on every managed device. Attackers get code execution across the whole fleet of endpoints the server manages, and the flaw is known to be exploited, including in ransomware campaigns.","severity":"critical","cvss":9.8,"epss":0.29551,"exploited":true,"exploited_at":"2022-04-13T00:00:00+00:00","products":[{"name":"Kaseya Virtual System/Server Administrator (VSA)","fixed":[],"affected":"","ecosystem":"vendor"}],"ecosystems":["vendor"],"tags":["exploited","kaseya-vsa","msp","ransomware","rmm","vendor"],"not_affected_if":["not-running-kaseya-vsa"],"how_to_check":null,"fix":"Apply the Kaseya-provided updates for VSA per vendor instructions (CISA required action); the specific fixed version is unknown from the sources.","status":"open","published_at":"2019-02-05T06:29:00+00:00","first_seen_at":"2026-10-23T19:11:52+00:00","triaged_at":"2026-10-23T21:17:58+00:00","updated_at":"2026-10-23T21:57:35+00:00","category":"vendor","confidence":0.6,"triage":{"at":"2026-10-23T21:17:58Z","model":"claude-haiku-5-5","output":{"fix":"Apply the Kaseya-provided updates for VSA per vendor instructions (CISA required action); the specific fixed version is unknown from the sources.","reach":"internet","impact":"high","summary":"Kaseya VSA, a remote monitoring and management server, has a flaw that lets unauthenticated remote attackers run PowerShell payloads on every managed device. Attackers get code execution across the whole fleet of endpoints the server manages, and the flaw is known to be exploited, including in ransomware campaigns.","category":"vendor","who_cares":["kaseya-vsa","msp","rmm"],"confidence":0.6,"needs_auth":"no","worst_case":"Attacker runs PowerShell on all managed devices, enabling ransomware deployment","analyst_note":"Confirm the affected and fixed VSA versions and the vendor advisory URL, and get a concrete check for exposed VSA servers; sources give neither.","how_to_check":"unknown","needs_analyst":true,"not_affected_if":["not-running-kaseya-vsa"],"user_interaction":"no","needs_special_setup":"unknown","severity_if_unknown":"critical"},"cost_usd":0.000485,"input_tokens":2851,"output_tokens":399,"severity_before":"unknown"},"analyst_status":null,"analyst_note":null,"search":"'-2018':13A,16A '-20753':14A,17A '2018':106C '9.3.0.35':84C '9.4.0.36':87C '9.5.0.5':91C 'across':58B 'activ':108C 'administr':4A 'administrator':21A 'allow':92C 'attack':46B,54B,95C,107C 'campaign':78B 'code':9A,56B 'cve':12A,15A 'devic':53B,103C 'endpoint':63B 'everi':51B 'execut':10A,57B,97C 'exploit':23B,74B,109C 'flaw':41B,69B 'fleet':61B 'get':55B 'includ':75B 'januari':105C 'kaseya':1A,6A,18A,25B,31B,79C 'kaseya-vsa':24B 'known':71B 'let':43B 'manag':37B,52B,66B,102C 'monitor':35B 'msp':27B 'payload':49B,99C 'powershel':48B,98C 'r9.3':83C 'r9.4':85C 'r9.5':89C 'ransomwar':28B,77B 'remot':8A,34B,45B,94C 'rmm':29B,81C 'run':47B 'server':38B,65B 'system/server':3A,20A 'unauthent':44B 'unprivileg':93C 'vendor':30B 'virtual':2A,19A 'vsa':5A,7A,22A,26B,32B,80C 'vulner':11A,111C 'whole':60B 'wild':114C","nicknames":[],"mitigations":[],"who_affected":null,"tier":null,"verified":{},"analyst_revisit_at":null,"first_public_at":"2019-02-05T06:29:00+00:00","kev":{"dateAdded":"2022-04-13","dueDate":"2022-05-04","requiredAction":"Apply updates per vendor instructions.","knownRansomwareCampaignUse":"Known"},"cvss_vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","cvss_by":"nvd@nist.gov","poc_count":0,"sources":[{"source":"kev","external_id":"CVE-2018-20753","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?search_api_fulltext=CVE-2018-20753","severity":null,"published_at":"2022-04-13T00:00:00+00:00","modified_at":null,"first_seen_at":"2026-10-23T19:11:52+00:00","fetched_at":"2026-10-25T10:39:06+00:00","note":null},{"source":"epss","external_id":"CVE-2018-20753","url":"https://api.first.org/data/v1/epss?cve=CVE-2018-20753","severity":null,"published_at":null,"modified_at":null,"first_seen_at":"2026-10-23T19:13:45+00:00","fetched_at":"2026-10-23T19:13:45+00:00","note":null},{"source":"nvd","external_id":"CVE-2018-20753","url":"https://nvd.nist.gov/vuln/detail/CVE-2018-20753","severity":null,"published_at":"2019-02-05T06:29:00+00:00","modified_at":"2026-08-13T05:17:18+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"}