CVE-2021-47878: eBeam Education Suite Privilege Escalation

CVE-2021-47878 Overview

CVE-2021-47878 is an unquoted service path vulnerability affecting eBeam Education Suite version 2.5.0.9. The vulnerability exists in the eBeam Device Service component, which allows local users to potentially execute arbitrary code with elevated privileges. Attackers with local access can exploit the unquoted path in the service configuration to inject malicious executables that would run with LocalSystem privileges during service startup.

Critical Impact

Local privilege escalation to SYSTEM level access through unquoted service path exploitation in educational software commonly deployed in school environments.

Affected Products

• eBeam Education Suite 2.5.0.9
• eBeam Device Service component

Discovery Timeline

• 2026-01-21 - CVE CVE-2021-47878 published to NVD
• 2026-01-21 - Last updated in NVD database

Technical Details for CVE-2021-47878

Vulnerability Analysis

This vulnerability is classified under CWE-428 (Unquoted Search Path or Element). The eBeam Device Service is configured with an unquoted service path containing spaces, which Windows interprets ambiguously when starting the service. When Windows encounters a service path with spaces that is not enclosed in quotation marks, it attempts to locate and execute files by parsing the path at each space character.

The local attack vector requires an attacker to have prior access to the target system, but does not require user interaction to exploit. The vulnerability affects the confidentiality, integrity, and availability of the system, as successful exploitation grants the attacker LocalSystem privileges—the highest privilege level on a Windows system.

Root Cause

The root cause is the improper configuration of the Windows service executable path. When the service path contains spaces and is not enclosed in quotation marks, Windows follows a predictable search order when attempting to resolve the executable path. For example, if the service path is C:\Program Files\eBeam Education Suite\Device Service\service.exe, Windows will attempt to execute files in the following order:

1. C:\Program.exe
2. C:\Program Files\eBeam.exe
3. C:\Program Files\eBeam Education.exe
4. C:\Program Files\eBeam Education Suite\Device.exe

An attacker who can place a malicious executable in any of these locations can hijack the service startup process.

Attack Vector

The attack requires local access to the system with sufficient permissions to write files to one of the searched paths. In many environments, the C:\ drive root or other directories in the search path may have overly permissive ACLs, allowing standard users to create files. When the eBeam Device Service starts (either at system boot or when manually restarted), the attacker's malicious executable runs with LocalSystem privileges.

This vulnerability is particularly concerning in educational environments where eBeam products are commonly deployed, as shared computer labs may have multiple users with local access, increasing the attack surface.

Detection Methods for CVE-2021-47878

Indicators of Compromise

• Presence of unexpected executables named Program.exe, eBeam.exe, Education.exe, or Device.exe in the C:\ root or C:\Program Files\ directory
• Suspicious process execution originating from the eBeam Device Service with unexpected behavior
• Unusual child processes spawned by services.exe corresponding to the eBeam service
• Modified or newly created files in directories along the unquoted service path

Detection Strategies

• Monitor for file creation events in C:\ and C:\Program Files\ directories for executables matching the path traversal pattern
• Implement Windows Security Event monitoring for Event ID 4688 (Process Creation) to detect anomalous process trees
• Use endpoint detection tools to scan for unquoted service paths across all installed services
• Deploy SentinelOne Singularity to detect and prevent privilege escalation attempts through behavioral analysis

Monitoring Recommendations

• Enable PowerShell logging and monitor for commands querying service configurations
• Configure audit policies to track file system changes in sensitive directories
• Implement application whitelisting to prevent unauthorized executable execution
• Use SentinelOne's Deep Visibility to correlate service-related events with suspicious file operations

How to Mitigate CVE-2021-47878

Immediate Actions Required

• Audit all Windows services for unquoted paths using PowerShell or dedicated scanning tools
• Verify and restrict file system permissions on directories in the service path hierarchy
• Apply the principle of least privilege for user accounts with local access
• Consider disabling the eBeam Device Service if not actively required until a patch is available

Patch Information

Users should check for updated versions of eBeam Education Suite from the vendor. Additional information may be available through the VulnCheck Advisory and the Exploit-DB entry for this vulnerability. The eBeam Download Resource may contain updated software versions.

Workarounds

• Manually correct the service path by adding quotation marks around the executable path in the Windows Registry
• Restrict write permissions on C:\ and C:\Program Files\ to administrators only
• Deploy application control policies to prevent execution of unauthorized binaries from vulnerable path locations
• Monitor the affected service for unauthorized modifications using file integrity monitoring

# PowerShell command to identify unquoted service paths
Get-WmiObject -Class Win32_Service | Where-Object { $_.PathName -notlike '"*' -and $_.PathName -like '* *' } | Select-Object Name, PathName

# Manually fix the registry entry (requires Administrator privileges)
# Navigate to: HKLM\SYSTEM\CurrentControlSet\Services\eBeamDeviceService
# Modify the ImagePath value to include quotation marks around the full path