Improper server-side validation in ScreenConnect extension framework

In versions of ScreenConnect™ prior to 25.8, server-side validation and integrity checks within the extension subsystem could allow the installation and execution of untrusted or arbitrary extensions by authorized or administrative users. Abuse of this behavior could result in the execution of custom code on the server or unauthorized access to application configuration data. This issue affects only the ScreenConnect server component; host and guest clients are not impacted. ScreenConnect 25.8 introduces enhanced server-side configuration handling and integrity checks to ensure only trusted extensions can be installed.

ScreenConnect Client: Guest-to-Host File Execution via File-Transfer Actions

A condition in the ScreenConnect client may allow files to be transferred and executed through an active remote session without authorization or Host confirmation in certain circumstances. ScreenConnect servers are not impacted.

Authenticated Host Pass Creation Allows Arbitrary Token Expiration in ScreenConnect

In ScreenConnect™ versions prior to 26.2, input validation within the Host Pass creation functionality could allow an authenticated user with Host Pass creation privileges the ability to specify a token expiration duration beyond the intended maximum when generating delegated access tokens.

ScreenConnect Instance Level Cryptographic Material Exposure

A condition in the ScreenConnect server component may allow an actor with access to server-level cryptographic material used for authentication to obtain unauthorized access, including elevated privileges, in certain scenarios. ScreenConnect host and guest client agents are not independently affected by this CVE.

Improper limitation of a pathname to a restricted directory (“path traversal”)

ConnectWise ScreenConnect 23.9.7 and prior are affected by path-traversal vulnerability, which may allow an attacker the ability to execute remote code or directly impact confidential data or critical systems.

ScreenConnect Exposure to ASP.NET ViewState Code Injection

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.

Authentication bypass using an alternate path or channel

ConnectWise ScreenConnect 23.9.7 and prior are affected by an Authentication Bypass Using an Alternate Path or Channel vulnerability, which may allow an attacker direct access to confidential information or critical systems.

Certificate Signing Extension Returns Encrypted Values

In deployments using the ScreenConnect™ Certificate Signing Extension, encrypted configuration values including an Azure Key Vault-related key, could be returned to unauthenticated users through a client-facing endpoint under certain conditions. The values remained encrypted and securely stored at rest; however, an encrypted representation could be exposed in client responses. Updating the Certificate Signing Extension to version 1.0.12 or higher ensures configuration handling occurs exclusively on the server side, preventing encrypted values from being transmitted to or rendered by client-side components.

ConnectWise ScreenConnect through 23.8.4 allows local users to connect to arbitrary relay servers via implicit trust of proxy settings

ConnectWise ScreenConnect through 23.8.4 allows man-in-the-middle attackers to achieve remote code execution via crafted messages.

ConnectWise - ScreenConnect Session Code Bypass

ConnectWise ScreenConnect versions 22.6 and below contained a flaw allowing potential brute force attacks on custom access tokens due to inadequate rate-limiting controls in the default configuration. Attackers could exploit this vulnerability to gain unauthorized access by repeatedly attempting access code combinations. ConnectWise has addressed this issue in later versions by implementing rate-limiting controls as a preventive measure against brute force attacks.