CVE-2025-3935

CVE Enrichment

CVSS: 7.2 HIGH
EPSS: 3.51%
EPSS Percentile: 88.89%
CISA KEV: YES — Known Exploited 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. It is important to note that to obtain these machine keys, privileged system level access must be obtained. If 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. The 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.

Technical Details

CVSS Version: 3.1
CNA / NVD Source: 7d616e1a-3288-43b1-a0dd-0a65d3e70a49
Published: 26-Apr-2025 02:15
Last Modified: 17-Jun-2026 16:20
EPSS Date: 2026-10-10
CWE: CWE-502

CVSS Vector


            CVSS:3.1                            AV:N /
                            AC:L /
                            PR:H /
                            UI:N /
                            S:U /
                            C:H /
                            I:H /
                            A:H

CISA KEV Details

Date Added: 2025-06-02
Remediation Due: 2025-06-23
Known Ransomware Campaign Use: Unknown
Required Action: Apply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
Notes: https://www.connectwise.com/company/trust/security-bulletins/screenconnect-security-patch-2025.4 ; https://nvd.nist.gov/vuln/detail/CVE-2025-3935

Affected Products / Versions

connectwise / screenconnect
Version / affected range: * · before (exclusive) 25.2.4
cpe:2.3:a:connectwise:screenconnect:*:*:*:*:*:*:*:*

References

Last enrichment sync: 13-Oct-2026 14:27
Sources: NVD · FIRST EPSS · CISA KEV
Latest successful provider update; providers refresh independently.

Reported Context (1)

ConnectWise disclosed a breach of its cloud-hosted ScreenConnect infrastructure, likely linked to CVE-2025-3935, a critical ViewState injection flaw. Threat actors also experimented with Authenticode stuffing, AsyncRAT Campaign Uses Trojanized ScreenConnect Installers and Open Directories

Malware (1)

MITRE ATT&CK (9)

Vendors (1)

Products (4)

Tools (1)

Industries (1)

Countries (4)

Note: Related entities, including threat actors, malware, CVEs, MITRE ATT&CK techniques, vendors, products, tools, countries, and industries, are shown when they appear in the same reporting. Their presence does not necessarily mean they were targeted, compromised, vulnerable, responsible for the activity, or directly involved in the incident.