CVE-2026-9634 in Redundancy Module Configuration Tool
Summary
by MITRE • 09/01/2026
A security issue exists within the Redundancy Module Configuration Tool. The RMConfigTool.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 represents a classic instance of insecure default permissions leading to unauthorized privilege escalation through dynamic link library hijacking. The core technical flaw lies in how the RMConfigTool.exe binary resolves its dependencies during execution. Rather than specifying absolute paths for required DLLs, the tool relies on the standard Windows search order, which includes directories listed in the system PATH environment variable. This design choice introduces a significant security risk because several of these directories are configured with default permissions that allow write access to non-administrator users. In many enterprise environments, particularly those utilizing shared workstations or specific service accounts, local user accounts possess modify rights over certain system-level folders such as C:\Windows\System32\config\systemprofile\AppData\Local\Temp or other temporary directories included in the PATH. This misconfiguration creates a predictable attack vector where any authenticated user on the system can manipulate files within these writable locations without requiring elevated privileges themselves.
The operational impact of this vulnerability is severe, facilitating an unprivileged local privilege escalation to Administrator or SYSTEM levels depending on how the tool is invoked and its manifest settings. The exploitation process begins when a malicious actor crafts a DLL that mimics the name and interface of one of the legitimate dependencies required by RMConfigTool.exe. This malicious binary contains code designed to execute arbitrary commands, establish persistence mechanisms, or exfiltrate sensitive data from the elevated context. Once placed in a writable directory within the PATH search order, the payload remains dormant until an administrator runs the configuration tool. Upon execution, Windows loads the attacker-controlled DLL into the process space of RMConfigTool.exe before loading the legitimate library if it exists later in the path or fails to load entirely due to name collision. Consequently, the malicious code executes with the full trust and privileges of the administrative account that launched the application. This effectively bypasses all local security boundaries enforced by standard user accounts, granting the attacker complete control over the system under a high-privilege context.
From a threat modeling perspective, this vulnerability aligns closely with CWE-284 Improper Access Control regarding default permissions and CWE-427 Uncontrolled Search Path Element which describes the failure to restrict search paths for external resources. In terms of adversary tactics as defined by MITRE ATT&CK, this scenario maps directly to T1574.007 DLL Side-Loading or Hijacking under the Defense Evasion technique category. Attackers frequently leverage such misconfigurations because they do not require exploiting a software bug in the traditional sense but rather exploit operational and configuration weaknesses inherent in how applications are deployed and secured within an organization. The reliance on relative paths or system PATH resolution for critical binaries is a common anti-pattern that security teams must actively monitor, as it provides a reliable method for lateral movement and initial access persistence when combined with social engineering tactics to induce administrators to run specific tools.
Mitigation strategies should focus on both immediate remediation of the application configuration and broader systemic hardening measures. The most effective technical fix is to modify RMConfigTool.exe or its deployment package to use absolute paths for all dependent DLLs, thereby removing reliance on the system PATH search order entirely. If modifying the binary is not feasible due to vendor constraints, administrators should audit the permissions of all directories included in the user and system PATH variables. Any directory that contains writable access for standard users but also serves as a location where privileged applications might load libraries must have its write permissions revoked or restricted exclusively to Administrators and SYSTEM accounts. Additionally, implementing Application Control policies such as Microsoft AppLocker or Windows Defender Application Control can prevent unauthorized DLLs from loading into elevated processes regardless of file placement. Regular auditing of PATH variables and enforcing the principle of least privilege on system directories are essential steps in preventing this class of vulnerability across the enterprise environment.