{"id":"CVE-2025-3935","url":"https://www.cyber-defence.io/tools/cve/CVE-2025-3935","generatedAt":"2026-10-31T06:57:22.462Z","title":"ConnectWise ScreenConnect Improper Authentication Vulnerability","description":"ScreenConnect versions 25.2.3 and earlier versions may be susceptible to a ViewState code injection attack. ASP.NET Web Forms use ViewState to preserve page and control state, with data encoded using Base64 protected by machine keys. \nIt is important to note that to obtain these machine keys, privileged system level access must be obtained. \n\n\n\nIf these machine keys are compromised, attackers could create and send a malicious ViewState to the website, potentially leading to remote code execution on the server. \n\n\n\nThe risk does not originate from a vulnerability introduced by ScreenConnect, but from platform level behavior.  This had no direct impact to ScreenConnect Client. ScreenConnect 2025.4 patch disables ViewState and removes any dependency on it.","published":"2025-04-25T19:15:49.000Z","lastModified":"2026-06-17T09:20:57.000Z","status":"Analyzed","sourceIdentifier":"7d616e1a-3288-43b1-a0dd-0a65d3e70a49","cvss":{"version":"3.1","score":7.2,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H"},"cwe":["CWE-502"],"affected":["connectwise/screenconnect"],"epss":{"score":0.03597,"percentile":0.89439,"date":"2026-10-30","history":[]},"kev":{"listed":true,"dateAdded":"2025-06-02","dueDate":"2025-06-23","knownRansomwareCampaignUse":"Unknown","notes":"Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.\nhttps://www.connectwise.com/company/trust/security-bulletins/screenconnect-security-patch-2025.4 ;   https://nvd.nist.gov/vuln/detail/CVE-2025-3935"},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"Known to be exploited in the wild (CISA KEV, CISA remediation deadline 23 June 2025). Treat as an emergency change: patch or isolate now, then hunt for prior compromise."},"changes":[],"references":[{"url":"https://www.connectwise.com/company/trust/advisories","tags":["Vendor Advisory"],"source":"7d616e1a-3288-43b1-a0dd-0a65d3e70a49"},{"url":"https://www.connectwise.com/company/trust/security-bulletins/screenconnect-security-patch-2025.4","tags":["Vendor Advisory"],"source":"7d616e1a-3288-43b1-a0dd-0a65d3e70a49"},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2025-3935","tags":["US Government Resource"],"source":"134c704f-9b21-4f2e-91b3-4a467353bcc0"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2025-3935","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}