CVE-2026-1585: IJ Scan Utility Privilege Escalation Flaw

CVE-2026-1585 Overview

An unquoted Windows service executable path vulnerability has been identified in Canon IJ Scan Utility for Windows versions 1.1.2 through 1.5.0. This privilege escalation vulnerability may allow a local attacker to execute a malicious file with the privileges of the affected service, potentially leading to full system compromise.

Critical Impact

Local attackers with access to the system can exploit the unquoted service path to execute arbitrary code with elevated privileges, potentially gaining complete control over the affected system.

Affected Products

• Canon IJ Scan Utility for Windows version 1.1.2
• Canon IJ Scan Utility for Windows versions through 1.5.0
• Windows systems running vulnerable Canon IJ Scan Utility installations

Discovery Timeline

• 2026-02-27 - CVE CVE-2026-1585 published to NVD
• 2026-03-03 - Last updated in NVD database

Technical Details for CVE-2026-1585

Vulnerability Analysis

This vulnerability is classified under CWE-428 (Unquoted Search Path or Element), a well-known Windows-specific security weakness that occurs when service executable paths containing spaces are not properly enclosed in quotation marks.

When Windows services are configured with unquoted paths containing spaces, the operating system's path parsing mechanism attempts to locate the executable by evaluating path segments from left to right. An attacker who can place a malicious executable in a higher-priority path location can hijack the service execution flow.

The vulnerability requires local access and elevated privileges to exploit, but successful exploitation grants the attacker the ability to execute arbitrary code with the privileges of the affected Canon IJ Scan Utility service. This typically includes SYSTEM-level privileges, making this a significant privilege escalation risk in enterprise environments.

Root Cause

The root cause of this vulnerability is improper configuration of the Windows service executable path for Canon IJ Scan Utility. When the service was registered, the path to the executable was not enclosed in double quotes. Since Windows paths often contain spaces (e.g., C:\Program Files\Canon\IJ Scan Utility\Application.exe), the operating system's CreateProcess function interprets the path ambiguously when quotes are absent.

Windows attempts to resolve the path by testing progressively longer portions of the string as potential executable names: first C:\Program.exe, then C:\Program Files\Canon\IJ.exe, and so forth. If an attacker can write to any of these locations (such as C:\), they can plant a malicious executable that Windows will run instead of the intended Canon application.

Attack Vector

This vulnerability requires local access to the target system. An attacker must have sufficient privileges to write executable files to locations within the unquoted path hierarchy. Common exploitation scenarios include:

A local user with write access to the root of the system drive (C:\) can place a malicious executable named Program.exe which will be executed when the Canon IJ Scan Utility service starts or restarts. The malicious code then inherits the privileges of the service, typically SYSTEM or a high-privilege service account.

The attack surface includes service restarts, system reboots, or any trigger that causes the vulnerable service to reinitialize. Once exploited, the attacker achieves privilege escalation from a low-privileged user to SYSTEM-level access.

Detection Methods for CVE-2026-1585

Indicators of Compromise

• Presence of unexpected executables named Program.exe, IJ.exe, or similar in the root drive or C:\Program Files\Canon\ directories
• Suspicious service execution events showing unexpected parent processes for Canon IJ Scan Utility
• Windows Security Event Log entries indicating service path manipulation or unexpected process execution
• File system audit logs showing creation of executables in sensitive path locations

Detection Strategies

• Query Windows services for unquoted paths containing spaces using PowerShell: Get-WmiObject win32_service | Where-Object {$_.PathName -notlike '"*"' -and $_.PathName -like '* *'}
• Monitor for file creation events in root directories and common interception paths
• Implement SentinelOne Singularity endpoint protection for real-time detection of privilege escalation attempts
• Deploy YARA rules to detect known exploit patterns targeting unquoted service paths

Monitoring Recommendations

• Enable Windows Security Event logging for process creation (Event ID 4688) with command line auditing
• Configure file integrity monitoring on critical directories including C:\ and C:\Program Files\
• Implement SentinelOne Behavioral AI to detect anomalous service execution patterns
• Regularly audit installed services for unquoted path vulnerabilities as part of security hygiene

How to Mitigate CVE-2026-1585

Immediate Actions Required

• Update Canon IJ Scan Utility for Windows to a version newer than 1.5.0 from the official Canon download portal
• Verify service paths are properly quoted after updating by inspecting the Windows Registry
• Audit the system for potential exploitation artifacts such as unexpected executables in path interception locations
• Remove any unauthorized files found in C:\ or along the unquoted path segments

Patch Information

Canon has released security advisories and remediation guidance for this vulnerability. Affected users should download and install the latest version of IJ Scan Utility for Windows from Canon's official support channels. Detailed remediation instructions are available through the Canon PSIRT Advisory CP2026-002 and the Canon USA Product Advisory CPA2026-002.

Additional vendor resources include the Canon Japan Vulnerability Response and Canon Europe Product Security pages.

Workarounds

• Manually add quotation marks around the service executable path in the Windows Registry (HKLM\SYSTEM\CurrentControlSet\Services\[ServiceName]\ImagePath)
• Restrict write permissions on root directories and intermediate path locations to prevent malicious file placement
• Disable the Canon IJ Scan Utility service if not required until the official patch can be applied
• Implement application whitelisting to prevent unauthorized executables from running in sensitive directories

# Configuration example
# PowerShell command to identify unquoted service paths
Get-WmiObject win32_service | Select-Object Name, PathName | Where-Object { $_.PathName -notmatch '^".*"$' -and $_.PathName -match '\s' } | Format-Table -AutoSize

# Manual fix via sc command (requires Administrator privileges)
# sc config "CanonIJScanUtility" binPath= "\"C:\Program Files\Canon\IJ Scan Utility\Application.exe\""