CVE-2025-3935 - ConnectWise ScreenConnect
AI Vulnerability ContextScreenConnect 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 ma...
Overview
A source-backed snapshot of 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.
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.
Vulnerability status
How serious this vulnerability is and whether it is known to be exploited.
- CVE ID
- CVE-2025-3935
- Vendor/project
- ConnectWise
- Product
- ScreenConnect
- Vulnerability name
- ConnectWise ScreenConnect Improper Authentication Vulnerability
- Date added
- 2025-06-02
- Due date
- 2025-06-23
- Known ransomware campaign use
- Unknown
- CVSS v3
- 8.1
Exploit context
What the vulnerability is about.
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.
Source evidence
Original public records and references for this page.
Original source
Original source links
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