CISA KEV · Known exploitedHigh

CVE-2025-3935

ConnectWise ScreenConnect

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...

CVSS: 7.2
EPSS: 3.42%
CISA KEV: Listed
Published: 2025.04.26

PRIORITY ASSESSMENT

Immediate review

CISA has listed this vulnerability in the Known Exploited Vulnerabilities catalog.

Known exploitationConfirmed by CISA KEV

Exploit probability3.42%

Technical severityCVSS 7.2

Vulnerability overview

Affected product and versions

Product: ConnectWise ScreenConnect
Affected versions: <25.2.3, < 25.2.4
Fixed versions: 25.2.4

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

CISA 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.

Due date: 2025.06.23

1
Identify
Confirm that ConnectWise ScreenConnect and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
CWE: CWE-287, CWE-502
KEV added: 2025.06.02
Ransomware use: 미확인