CVE-2025-34352: JumpCloud Remote Assist Escalation Flaw

CVE-2025-34352 Overview

CVE-2025-34352 affects JumpCloud Remote Assist for Windows versions prior to 0.317.0. The Remote Assist uninstaller is invoked by the JumpCloud Windows Agent as NT AUTHORITY\SYSTEM during uninstall or update operations. It performs privileged file operations inside a user-writable %TEMP% subdirectory without validating trust or resetting ACLs. A local, low-privileged attacker can pre-create the directory with weak permissions and abuse mount-point or symbolic-link redirection [CWE-59] to coerce arbitrary file writes or deletions. Successful exploitation enables denial of service, arbitrary file deletion, and local privilege escalation to SYSTEM.

Critical Impact
Local low-privileged attackers can escalate to SYSTEM on Windows endpoints where JumpCloud Remote Assist is managed by the JumpCloud Agent.

Affected Products

JumpCloud Remote Assist for Windows versions prior to 0.317.0
Windows endpoints managed by the JumpCloud Windows Agent
Systems where Remote Assist lifecycle (install, update, uninstall) is orchestrated by the Agent

Discovery Timeline

2025-12-02 - CVE-2025-34352 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-34352

Vulnerability Analysis

The flaw resides in the Remote Assist uninstaller executed by the JumpCloud Windows Agent during uninstall or update operations. The uninstaller runs as NT AUTHORITY\SYSTEM and creates, writes, executes, and deletes files inside a predictable subdirectory of the user-writable %TEMP% path. It does not validate that the directory is trusted, and it does not reset the access control list (ACL) when the directory already exists.

Because %TEMP% locations are writable by unprivileged users, an attacker can stage the directory ahead of time. When the SYSTEM-level uninstaller later reuses that directory, its privileged file operations act on attacker-controlled paths. This is a classic link-following weakness tracked under [CWE-59].

Root Cause

The uninstaller trusts a predictable directory path in a user-writable location without verifying ownership or resetting ACLs. Privileged operations proceed against paths the attacker controls, creating a link-following primitive that yields arbitrary file write and arbitrary file delete as SYSTEM.

Attack Vector

An authenticated local attacker pre-creates the target subdirectory under %TEMP% with weak permissions. The attacker then plants a mount point or symbolic link redirecting operations to a protected target. When the JumpCloud Agent triggers the Remote Assist uninstaller as SYSTEM, the attacker races DeleteFileW() to redirect deletion to attacker-chosen files or folders. The same primitive supports coerced writes into protected locations, producing denial of service by overwriting system files or enabling local privilege escalation to SYSTEM.

For further technical context, see the VulnCheck Advisory on JumpCloud Remote Assist.

Detection Methods for CVE-2025-34352

Indicators of Compromise

Presence of a pre-existing Remote Assist working directory under a user's %TEMP% with non-default ACLs granting Everyone or Users write access
Mount points (junctions) or symbolic links within user %TEMP% subdirectories pointing to protected paths such as C:\Windows\System32
Unexpected deletion or modification of privileged system files coinciding with JumpCloud Agent uninstall or update activity
Repeated low-privileged process activity creating or recreating directories used by the Remote Assist uninstaller

Detection Strategies

Monitor file-system telemetry for reparse point creation (IO_REPARSE_TAG_MOUNT_POINT, IO_REPARSE_TAG_SYMLINK) inside user-writable %TEMP% paths.
Correlate SYSTEM-context file writes and DeleteFileW() operations with a parent process chain originating from the JumpCloud Windows Agent.
Alert on JumpCloud Agent uninstall or upgrade events on hosts still running Remote Assist versions prior to 0.317.0.

Monitoring Recommendations

Inventory endpoints running JumpCloud Remote Assist and flag versions below 0.317.0.
Track Agent lifecycle events (install, update, uninstall) with timestamps to enable retrospective hunting against file-system telemetry.
Establish baselines for reparse point usage inside per-user %TEMP% directories and alert on deviations.

How to Mitigate CVE-2025-34352

Immediate Actions Required

Upgrade JumpCloud Remote Assist to version 0.317.0 or later on all affected Windows endpoints.
Audit %TEMP% subdirectories used by Remote Assist for weak ACLs and remove any junctions or symbolic links pointing to protected locations.
Restrict local logon on high-value hosts to reduce the population of accounts able to stage the attack.

Patch Information

JumpCloud has fixed this issue in Remote Assist 0.317.0. Review the JumpCloud Agent Release Notes to confirm rollout status and validate the deployed version on managed endpoints. Additional product context is available on the JumpCloud Remote Assistance overview.

Workarounds

Defer JumpCloud Agent uninstall or update operations on affected Windows systems until Remote Assist 0.317.0 is deployed.
Where feasible, remove Remote Assist from endpoints that do not require it to eliminate the vulnerable uninstaller path.
Harden ACLs on per-user %TEMP% directories and enable auditing for reparse point creation to detect staging attempts.

bash

# Verify installed JumpCloud Remote Assist version on a Windows host (PowerShell)
Get-ItemProperty "HKLM:\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall\*" |
  Where-Object { $_.DisplayName -like "*JumpCloud Remote Assist*" } |
  Select-Object DisplayName, DisplayVersion, InstallLocation