SARA / Free Tools / CVE / CVE-2025-3935

CVE-2025-3935 — ConnectWise ScreenConnect Improper Authentication Vulnerability

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 m

CVSS
8.1 HIGH
EPSS
15.50% (top 5.40%)
CWE
CWE-502
Published
2025-04-25T18:27:44.244Z
Last modified
2026-02-26T18:28:01.567Z
CVSS vector
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
CISA KEV — Actively Exploited
Added to KEV
2025-06-02
BOD 22-01 due
2025-06-23
Ransomware use
Unknown

01What is this vulnerability?

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.

02Affected products

VendorProductVersions
ConnectWiseScreenConnect<25.2.3

03Active exploitation status

Yes — actively exploited. Added to the CISA KEV catalog on 2025-06-02. Ransomware use: Unknown.

04Recommended remediation

05Technical details

For the full vendor write-up, exploit chains, and reference implementations, see the references list in section 09.

06Detection signatures

Open the Sigma generator with a pre-filled prompt for this CVE to draft a starting detection in your stack of choice:

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07Related CVEs

No directly-cited follow-up CVEs in the KB record for this advisory. The references list in section 09 carries the vendor cross-references.

08Timeline

09References

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