EUVD-2026-47622
GHSA-fc5x-r66h-vp5f
Severity by source
AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:H
Local low-privileged user (AV:L/PR:L), deterministic no-interaction chain (AC:L/UI:N), crosses boundary to SYSTEM with full impact (S:C, C/I/A:H).
Primary rating from Vendor (NCSC.ch).
CVSS VectorVendor: NCSC.ch
Lifecycle Timeline
2DescriptionCVE.org
The servereye client (also known as sensorhub, technically ClientAgentContainerService) versions 20.15 and earlier are vulnerable to Local Privilege Escalation. The high-privileged service SE3Recovery (EmergencyRecoveryService.exe), running as SYSTEM, periodically monitors the directory %ProgramData%\ServerEye3\update\ for a trigger file named "update_available". Due to insufficient access restrictions on this directory, a local standard user can create the trigger file and provide a path to a directory containing malicious JSON instructions. The service subsequently executes the utility UpdaterAction.exe with SYSTEM privileges, which parses the instructions and performs an unvalidated file copy from a user-controlled source to a protected system destination (e.g., overwriting a service binary). This leads to full system compromise as the service automatically restarts the overwritten binary with SYSTEM privileges.
AnalysisAI
Local privilege escalation in the servereye Windows agent (Sensorhub / ClientAgentContainerService) versions 20.15 and earlier lets any local standard user gain SYSTEM. The SYSTEM-level SE3Recovery service (EmergencyRecoveryService.exe) watches a world-writable directory for a trigger file and then runs UpdaterAction.exe, which performs an unvalidated file copy from a user-controlled source over a protected service binary, resulting in full system compromise. No public exploit identified at time of analysis; this was reported by NCSC.ch and is not listed in CISA KEV, so there is no evidence of active exploitation.
Technical ContextAI
The affected component is servereye's monitoring agent, an RMM/monitoring tool used primarily by managed service providers. The root cause is CWE-379 (creation/consumption of files in a directory with insecure permissions): the privileged SE3Recovery recovery service polls %ProgramData%\ServerEye3\update\ for a trigger file named 'update_available'. Because that ProgramData subdirectory grants write access to standard users, an unprivileged user controls both the trigger file and the JSON instruction path it references. The service passes those attacker-controlled instructions to UpdaterAction.exe running as SYSTEM, which then copies a user-supplied file to a protected destination without validating source or destination, enabling an arbitrary file write/overwrite of a service binary. Automatic restart of the overwritten service converts that file write directly into SYSTEM-level code execution.
RemediationAI
Upgrade the servereye Sensorhub/Windows agent to a fixed release per the vendor bulletin at https://www.servereye.de/security-bulletins/2026-001/ (Patch available per vendor advisory); the provided data does not state an exact patched version number, so confirm the target build directly with servereye GmbH. As a compensating control until patched, harden the ACL on %ProgramData%\ServerEye3\update\ so that standard (non-administrator) users cannot create or write files there, which removes the attacker's ability to plant the 'update_available' trigger and the instruction path - with the trade-off that any legitimate low-privileged update/recovery workflow relying on that directory may break, so validate the feature still functions afterward. Additionally, monitor for creation of the 'update_available' trigger file and for unexpected writes to servereye service binaries, and restrict interactive/local logon on hosts running the agent to shrink the pool of accounts that could abuse it.
Same technique Privilege Escalation
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External POC / Exploit Code
Leaving vuln.today