CVE-2025-3935 KEV
Patch first
On CISA KEV — known exploited in the wild, due 2025-06-23.
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.
Scoring
| CVSS | 8.1 (HIGH, v3.1) |
|---|---|
| Vector | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H |
| EPSS | 3.51% — more likely to be exploited than 89% of all CVEs |
| Weakness | CWE-502 |
| On CISA KEV | yes — remediate by 2025-06-23 |
| Public exploit | none known |
| Published | 2025-04-25 |
| Last modified | 2026-06-17 |
CISA KEV
| Name | ConnectWise ScreenConnect Improper Authentication Vulnerability |
|---|---|
| Added | 2025-06-02 |
| Due | 2025-06-23 |
| Vendor / product | ConnectWise / ScreenConnect |
| Ransomware use | none reported |
Affected (1)
| Vendor | Product |
|---|---|
| connectwise | screenconnect |
References
→ the Explorer · watch your stack · NVD