CVE-2023-52945: Synology BeeDrive RCE Vulnerability

CVE-2023-52945 Overview

CVE-2023-52945 is an uncontrolled search path element vulnerability in the OpenSSL Dynamic Link Library (DLL) component used by Synology BeeDrive for desktop. Versions prior to 1.3.2-13814 load DLLs from insecure locations, allowing local users to execute arbitrary code through unspecified vectors. The flaw is classified under CWE-427: Uncontrolled Search Path Element. Successful exploitation results in code execution within the security context of the BeeDrive process.

Critical Impact

Local attackers can place a malicious DLL in a path searched by BeeDrive before the legitimate OpenSSL library, achieving arbitrary code execution with high impact to confidentiality, integrity, and availability.

Affected Products

• Synology BeeDrive for desktop versions before 1.3.2-13814
• OpenSSL DLL component bundled with BeeDrive desktop client
• Windows endpoints running vulnerable BeeDrive installations

Discovery Timeline

• 2026-05-27 - CVE-2023-52945 published to the National Vulnerability Database (NVD)
• 2026-05-27 - Last updated in NVD database

Technical Details for CVE-2023-52945

Vulnerability Analysis

The vulnerability resides in how Synology BeeDrive resolves and loads its bundled OpenSSL DLL at runtime. The application does not enforce a fully qualified path when loading the library. Windows therefore falls back to its standard DLL search order, which includes the application's working directory and other writable locations.

A local attacker who can write a file to a directory present in the search path can plant a malicious DLL with the expected OpenSSL filename. When BeeDrive starts or invokes the affected functionality, the planted DLL loads instead of the legitimate library. Code in the attacker-controlled DLL executes within the BeeDrive process context.

The CWE-427 classification confirms the root issue is path resolution rather than a memory safety defect. The attack requires local access and low privileges but does not require user interaction beyond normal application use.

Root Cause

The BeeDrive client invokes the OpenSSL DLL without specifying an absolute path or applying SetDefaultDllDirectories style hardening. Windows resolves the DLL name using the default search order, which can include user-writable directories. This permits substitution of the legitimate library with an attacker-supplied binary that exports the same symbols.

Attack Vector

Exploitation requires local file system access on a Windows host where BeeDrive is installed. An attacker writes a crafted DLL bearing the OpenSSL filename expected by BeeDrive into a directory searched before the install path. On the next BeeDrive process start or library load, the malicious DLL is mapped into the process. The DLL's DllMain or exported functions then execute attacker code with the user's privileges. No verified public proof-of-concept is currently available; refer to the Synology Security Advisory SA-24-26 for vendor-confirmed details.

Detection Methods for CVE-2023-52945

Indicators of Compromise

• Unsigned or unexpected libcrypto, libssl, or related OpenSSL DLL files located in BeeDrive working directories or user-writable paths
• BeeDrive processes loading OpenSSL DLLs from paths outside the official installation directory
• New DLL files appearing in directories adjacent to the BeeDrive executable shortly before process launch
• Child processes spawned by BeeDrive that do not match expected synchronization activity

Detection Strategies

• Monitor image load events (Sysmon Event ID 7) for BeeDrive processes loading DLLs from non-standard locations
• Compare hashes of loaded OpenSSL DLLs against vendor-published values from the Synology Security Advisory SA-24-26
• Alert on file write operations placing DLLs into BeeDrive's current working directory by non-installer processes
• Inspect digital signatures of all DLLs loaded by BeeDrive.exe and flag unsigned or untrusted publishers

Monitoring Recommendations

• Enable detailed module load auditing on endpoints running BeeDrive
• Track BeeDrive version inventory and flag hosts running builds older than 1.3.2-13814
• Forward Sysmon and EDR telemetry to a central data lake for retrospective hunting against DLL search order abuse patterns mapped to MITRE ATT&CK technique T1574.001

How to Mitigate CVE-2023-52945

Immediate Actions Required

• Upgrade Synology BeeDrive for desktop to version 1.3.2-13814 or later on all affected Windows endpoints
• Inventory all systems running BeeDrive and prioritize patching of multi-user or shared workstations
• Remove any unauthorized DLL files found in BeeDrive directories or user-writable paths in the application's search order
• Restrict write permissions on directories from which BeeDrive loads libraries

Patch Information

Synology released the fix in BeeDrive for desktop 1.3.2-13814. The corrected build resolves the OpenSSL DLL through hardened search path logic. Patch details and download instructions are available in the Synology Security Advisory SA-24-26.

Workarounds

• Where patching cannot occur immediately, restrict local logon rights to trusted users only
• Apply NTFS access control lists that deny non-administrative write access to the BeeDrive installation directory and parent folders
• Use application allowlisting to block execution of unsigned DLLs from user-writable paths
• Disable or uninstall BeeDrive on hosts where the synchronization functionality is not required until the patch is applied