CVE-2025-57781: DENSO TEN Drive Recorder RCE Vulnerability

CVE-2025-57781 Overview

CVE-2025-57781 affects the installers of the DENSO TEN drive recorder viewer. The installers use an insecure Dynamic Link Library (DLL) search path, allowing attackers to load malicious DLLs from attacker-controlled locations. When a user runs a vulnerable installer, the process loads a planted DLL and executes arbitrary code with that user's privileges. The vulnerability is tracked as CWE-427: Uncontrolled Search Path Element.

Critical Impact
Successful exploitation results in arbitrary code execution with the privileges of the user invoking the installer, enabling local compromise of the host.

Affected Products

DENSO TEN drive recorder viewer installers
See the JVN Vulnerability Report for affected installer versions
See the Denso Ten Security Advisory for product-specific guidance

Discovery Timeline

2025-10-06 - CVE-2025-57781 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-57781

Vulnerability Analysis

The DENSO TEN drive recorder viewer installer loads DLLs without specifying a fully qualified path. Windows resolves the requested DLL name using its standard search order, which includes the current working directory and other writable locations before trusted system directories. An attacker who places a malicious DLL with a matching name in one of these earlier-searched locations causes the installer to load attacker code in-process. The flaw is classified as CWE-427: Uncontrolled Search Path Element, commonly known as DLL search-order hijacking or DLL preloading.

Root Cause

The installer relies on the default Windows DLL search behavior instead of calling protective APIs such as SetDefaultDllDirectories or loading dependencies with absolute paths. Because installers are frequently executed from user-writable directories like Downloads, a co-located DLL with the expected name is loaded ahead of any legitimate system copy.

Attack Vector

Exploitation requires local access and user interaction. An attacker delivers the legitimate installer alongside a malicious DLL — for example, inside a single archive or shared folder — and convinces the victim to execute the installer. When the installer starts, it resolves the planted DLL first and executes the attacker's DllMain code in the installer's process context. The attacker inherits the privileges of the invoking user, which is often an administrator during software installation.

No verified proof-of-concept code is publicly available. The vulnerability mechanism is described in prose only; refer to the JVN Vulnerability Report for vendor-confirmed technical details.

Detection Methods for CVE-2025-57781

Indicators of Compromise

Unexpected DLL files co-located with a DENSO TEN drive recorder viewer installer in user-writable directories such as Downloads or removable media
Installer processes loading DLLs from non-standard paths instead of C:\Windows\System32 or the installer's program directory
Child processes spawned by the installer that do not match expected DENSO TEN binaries

Detection Strategies

Monitor Microsoft-Windows-Sysmon Event ID 7 (Image Loaded) for installer executables loading DLLs from user profile or temporary directories
Hunt for installer processes whose loaded module path differs from the executable's parent directory or signed system paths
Alert on unsigned or untrusted DLLs loaded by installation binaries

Monitoring Recommendations

Enable Sysmon ImageLoad logging with filters scoped to installer executables and forward events to a centralized SIEM
Track file creation events that drop DLLs into the same directory as recently downloaded executables
Review endpoint telemetry for execution chains where an installer launches unexpected interpreters such as powershell.exe or cmd.exe

How to Mitigate CVE-2025-57781

Immediate Actions Required

Stop running existing copies of the DENSO TEN drive recorder viewer installer until the vendor-fixed version is obtained
Re-download the installer directly from DENSO TEN and verify it is the patched release before execution
Run installers only from a clean, dedicated directory that contains no other files

Patch Information

DENSO TEN has published guidance in the Denso Ten Security Advisory. Apply the fixed installer version listed in the advisory and the corresponding JVN Vulnerability Report.

Workarounds

Move the installer to an empty, trusted directory such as a freshly created folder before execution to remove any planted DLLs from the search path
Block execution of installers staged from Downloads or removable media using application control policies such as Windows Defender Application Control or AppLocker
Restrict standard users from running installers that require elevation, reducing the privileges available to attacker-loaded DLLs