High severity · published Apr 25, 2025
CVE-2025-3935
ScreenConnect Exposure to ASP.NET ViewState Code Injection
In wildKEV
7.2
CVSS
3.6%
EPSS
Yes
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
High
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)3.6% · higher than 89% of CVEs
Exploited in the wildYes
CISA KEVListed Jun 2, 2025
Federal remediation dueJun 23, 2025
Ransomware campaign useNot known
Affected products
Which versions
SC
ScreenConnect · ConnectWise
<25.2.3 · source: vendor, NVD, KEV
Affected product
SC
ScreenConnect
ConnectWise
More from ScreenConnect
10.0
CVE-2024-1709
Authentication bypass using an alternate path or channel
9.9
CVE-2026-84869
ScreenConnect Client: Guest-to-Host File Execution via File-Transfer Actions
8.4
CVE-2024-1708
Improper limitation of a pathname to a restricted directory (“path traversal”)
9.8
CVE-2023-25718
In ConnectWise Control through 22.9.10032 (formerly known as ScreenConnect), after an executable file is signed, additional instructions can be added without invalidating the…
9.8
CVE-2019-16517
An issue was discovered in ConnectWise Control (formerly known as ScreenConnect) 19.3.25270.7185