CVE-2026-9633 in Redundancy Module Configuration Tool
Summary
by MITRE • 09/01/2026
A security issue exists within the Redundancy Module Configuration Tool. The RM3ConfigTool.exe binary searches directories in the system path for a required DLL, and one or more of these directories may be writable by standard (non-administrator) users due to incorrect default permissions. If a local attacker places a malicious DLL in such a directory and an administrator subsequently runs the tool, the malicious DLL is loaded into the elevated process and executes with Administrator/SYSTEM privileges.
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Analysis
by VulDB Data Team • 09/01/2026
The vulnerability identified within the Redundancy Module Configuration Tool stems from a classic insecure library search order flaw, specifically categorized under CWE-427 as Uncontrolled Search Path for an Executable or Dynamic Link Library. The core technical issue lies in how the RM3ConfigTool.exe binary resolves dependencies on required dynamic link libraries. Instead of specifying absolute paths to trusted locations where these DLLs reside, the application relies on the system environment path variable to locate them. This design choice introduces a critical security gap because it assumes that all directories listed in the system path are secure and immutable by unauthorized users. In many Windows environments, particularly those with default configurations or improper permission settings, certain directories within the PATH such as C:\Windows\System32 or specific application folders may have write permissions granted to standard user accounts rather than being restricted exclusively to administrators.
When a local attacker identifies one of these writable directories in the system path, they can exploit this misconfiguration by placing a maliciously crafted DLL with the same name as the expected dependency into that location. This technique is known as DLL hijacking or DLL preloading. The attack vector relies on timing and privilege escalation dynamics. Once the malicious DLL is placed in the accessible directory, it remains dormant until an administrator launches the RM3ConfigTool.exe application. Upon execution, the operating system's dynamic linker searches the directories listed in the PATH variable sequentially to resolve the missing dependency. Because the attacker-controlled directory appears earlier or simply exists within this search path and contains a file with the matching name, the loader loads the malicious DLL instead of the legitimate one.
The operational impact of this vulnerability is severe due to the context in which the tool operates. Since RM3ConfigTool.exe is typically run by system administrators who possess elevated privileges, often including SYSTEM-level access depending on the specific configuration and deployment scenario, any code executed within its process inherits these high-level permissions. Consequently, when the malicious DLL is loaded into the administrator's session, it executes with full administrative or even SYSTEM rights. This allows an attacker to perform arbitrary actions such as creating new user accounts with admin privileges, modifying system configurations, installing backdoors, exfiltrating sensitive data, or pivoting to other systems on the network. The attack effectively bypasses standard access controls by leveraging legitimate software behavior to escalate privileges from a low-privileged account to a high-privileged one without requiring additional exploits or zero-day vulnerabilities in the operating system itself.
From an offensive security perspective, this vulnerability aligns with MITRE ATT&CK technique T1574.007, which describes DLL Search Order Hijacking as a method for achieving initial access and privilege escalation. It also relates to T1059.004, indicating the use of Windows binaries or scripts via command line interfaces if the tool is invoked through such means. The persistence aspect can be achieved by ensuring the malicious DLL remains in place across reboots, allowing continued potential for exploitation whenever administrative tools are used. This type of vulnerability highlights a common oversight in software development where convenience and ease of deployment override security best practices regarding file system permissions and path resolution strategies.
Mitigation requires both immediate remediation steps from the administrator's perspective and long-term fixes from the developer's standpoint. Administrators should immediately audit the directories listed in their system PATH variable for write access by standard users using tools like icacls or PowerShell cmdlets to identify insecure paths. Any directory that allows non-administrative modification of files within it, especially those containing executable binaries or DLLs, represents a risk and should have its permissions tightened so only trusted accounts can modify contents. Furthermore, administrators should ensure they run applications with the principle of least privilege whenever possible, avoiding unnecessary elevation unless absolutely required for configuration tasks.
For developers, the primary mitigation is to eliminate reliance on relative paths or system PATH lookups for critical dependencies. The application should be updated to use absolute paths pointing directly to known secure locations where DLLs are installed. Additionally, implementing SafeDllSearchMode can help mitigate some forms of search order hijacking by changing how Windows searches for DLLs, although this is not a complete fix if the application explicitly bypasses it or if writable directories remain in specific high-priority positions. Code signing and integrity checks on loaded libraries provide another layer of defense, ensuring that only verified binaries are executed within elevated processes. Regular security audits focusing on file system permissions and dependency management practices are essential to prevent similar vulnerabilities across enterprise software ecosystems.