Docker Desktop DLL Hijacking Vulnerability (CVE-2025-9164) – High-Severity Flaw Exposes Windows Systems to Local Privilege Escalation + Video

By /

Listen to this Post

Featured Image

Introduction:

A recently published high-severity vulnerability in Docker Desktop for Windows (CVE-2025-9164) exposes millions of systems to local privilege escalation through a classic DLL hijacking attack vector. The flaw, discovered and reported by security researcher Mahmoud NourEldin, stems from an insecure DLL search order in the Docker Desktop Installer.exe that prioritizes the user’s Downloads folder over trusted system directories. With a CVSS v4 score of 8.8 (HIGH), this vulnerability allows an attacker with local access to place a malicious DLL in the Downloads folder, which the installer will load with elevated privileges during installation, effectively granting the attacker SYSTEM-level access.

Learning Objectives:

  • Understand the technical mechanics of CWE-427 (Uncontrolled Search Path Element) and how it manifests in Docker Desktop’s installer.
  • Learn to identify, exploit (in a controlled lab environment), and remediate DLL hijacking vulnerabilities on Windows systems.
  • Acquire practical commands and configuration techniques to audit, monitor, and harden Windows endpoints against similar search-order attacks.

You Should Know:

1. Understanding CVE-2025-9164 – The DLL Hijacking Mechanism

Docker Desktop Installer.exe (versions up to and including 4.48.0) contains a dangerous flaw in its DLL loading routine. When the installer executes, it searches for required dynamic link libraries (DLLs) in a specific order. The vulnerability arises because the installer checks the user’s Downloads folder before examining standard system directories such as C:\Windows\System32. An attacker who can place a malicious DLL with a name matching a legitimate dependency (e.g., version.dll, winhttp.dll, or a Docker-specific library) into the Downloads folder can force the installer to load their rogue library instead of the genuine system file. Since the installer typically runs with elevated administrative privileges, the malicious code executes with those same high privileges, leading to a full system compromise.

This vulnerability is classified under CWE-427: Uncontrolled Search Path Element and maps to MITRE ATT&CK technique T1574 (Hijack Execution Flow). The attack is local in nature, requires low privileges to stage the malicious DLL, and does not require user interaction beyond the attacker having access to place a file in the Downloads directory.

Step‑by‑step guide: Understanding the Attack Flow

  1. Reconnaissance: The attacker identifies that the target system runs Docker Desktop for Windows version 4.48.0 or earlier. This can be done by checking the version via `docker version` or inspecting the installed programs list.
  2. DLL Identification: The attacker determines which DLLs the Docker Desktop installer attempts to load. This can be done using tools like `Process Monitor` (ProcMon) from Sysinternals to filter on `Process Name` containing `Install` and `Operation` being `Load Image` or `CreateFile` with `Path` ending in .dll.
  3. Malicious DLL Placement: The attacker crafts a malicious DLL that exports the same functions as the legitimate DLL (or uses a proxy DLL that forwards calls to the original while injecting malicious code) and places it in the `C:\Users\\Downloads` directory.
  4. Triggering the Installer: The attacker waits for the user to run the Docker Desktop installer (or triggers it through social engineering). When the installer runs, it loads the malicious DLL from the Downloads folder, executing the attacker’s code with SYSTEM privileges.
  5. Post-Exploitation: The attacker now has elevated access and can install persistent backdoors, exfiltrate sensitive data, or pivot to other systems on the network.

2. Impact Assessment and Affected Versions

All versions of Docker Desktop for Windows through 4.48.0 are affected by this vulnerability. Docker has released version 4.49.0 which addresses the insecure search path. The vulnerability was assigned a CVSS v3 base score of 7.8 (High) and a CVSS v4 score of 8.8 (High), reflecting the significant risk it poses. The attack complexity is rated as High due to the need for precise DLL naming and placement, but the privileges required are Low, and the scope is Changed, meaning the impact extends beyond the vulnerable component.

Step‑by‑step guide: Assessing Your Exposure

  1. Check Docker Desktop Version: Open a command prompt or PowerShell and run: 
    docker version

    Look for the `Client` and `Server` version information. Alternatively, check the version in the Docker Desktop GUI: click the Docker icon in the system tray → About Docker.

  2. Compare Against Vulnerable Versions: If the version is 4.48.0 or earlier, your system is vulnerable. Versions 4.49.0 and later are patched.
  3. Verify the Installer Path: The vulnerable installer is typically located at `C:\Program Files\Docker\Docker\resources\Docker Desktop Installer.exe` or in the downloads folder if a fresh installation is being performed.
  4. Audit the Downloads Folder: Check for any suspicious DLLs in the Downloads folder that could be loaded by the installer. Use PowerShell: 
    Get-ChildItem -Path "$env:USERPROFILE\Downloads.dll" -Recurse
  5. Review Event Logs: Search for DLL load events that might indicate exploitation attempts: 
    Get-WinEvent -LogName "Microsoft-Windows-Kernel-Process/Operational" | Where-Object { $_.Message -like "DLL" }

3. Exploitation Scenarios and Real-World Implications

In a real-world attack scenario, an adversary who has already gained limited access to a workstation (e.g., through phishing or a separate vulnerability) can leverage CVE-2025-9164 to escalate privileges to SYSTEM. The attack is particularly insidious because the Downloads folder is a common location where users store files, and many users run installers directly from this folder. An attacker could, for example, plant a malicious DLL named `msvcp140.dll` (a common Visual C++ runtime dependency) in the Downloads folder. When the user subsequently runs the Docker Desktop installer, the malicious DLL is loaded instead of the legitimate system DLL, granting the attacker elevated code execution.

In enterprise environments, this vulnerability poses a significant risk because Docker Desktop is widely deployed among developers and DevOps teams. A successful exploit could allow an attacker to compromise containerized applications, access sensitive credentials stored in Docker configurations, or move laterally across the network.

Step‑by‑step guide: Simulating the Attack (Lab Environment Only)

Warning: The following steps are for educational purposes in a controlled, isolated lab environment. Do not attempt on production systems.

  1. Set Up a Lab: Create a Windows virtual machine with Docker Desktop 4.48.0 installed.
  2. Create a Test DLL: Use Visual Studio or MinGW to create a simple DLL that writes a log entry to a file or pops a message box when loaded. For example, in C++: 
    include <windows.h>
BOOL APIENTRY DllMain(HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved) {
if (ul_reason_for_call == DLL_PROCESS_ATTACH) {
MessageBox(NULL, L"Malicious DLL Loaded!", L"Exploit", MB_OK);
}
return TRUE;
}
  3. Compile and Name the DLL: Compile the DLL and name it after a known dependency of the Docker installer (e.g., `version.dll` or winhttp.dll). Place it in the `C:\Users\\Downloads` folder.
  4. Run the Installer: Execute `Docker Desktop Installer.exe` from any location. The installer will search the Downloads folder and load the malicious DLL.
  5. Observe the Exploit: The message box will appear, confirming that the malicious DLL was loaded with the installer’s elevated privileges.
  6. Clean Up: Delete the malicious DLL and ensure the system is restored to a known good state.

4. Detection and Monitoring Strategies

Detecting exploitation of CVE-2025-9164 requires monitoring for unusual DLL loading patterns, particularly from the Downloads folder. Security teams should implement endpoint detection and response (EDR) solutions with rules that flag any process attempting to load a DLL from user-writable directories like Downloads, Desktop, or Temp folders. Additionally, system administrators should audit the Downloads folder regularly for unauthorized DLL files and consider implementing application whitelisting to block the execution of untrusted libraries.

Step‑by‑step guide: Implementing Detection Controls

  1. Enable Process Auditing: Use Windows Advanced Audit Policy to log process creation and DLL load events. Enable `Audit Process Creation` and `Audit Detailed File Share` under Computer Configuration → Windows Settings → Security Settings → Advanced Audit Policy Configuration.
  2. Configure Sysmon: Deploy Sysinternals Sysmon with a configuration that logs DLL image loads. Example configuration snippet to log DLL loads from user directories: 
    <Sysmon schemaversion="4.22">
<EventFiltering>
<ProcessAccess onmatch="exclude" />
<ImageLoad onmatch="include">
<ImageLoaded condition="contains">Downloads</ImageLoaded>
<ImageLoaded condition="contains">Desktop</ImageLoaded>
<ImageLoaded condition="contains">AppData</ImageLoaded>
</ImageLoad>
</EventFiltering>
</Sysmon>
  3. Monitor with PowerShell: Create a scheduled script that scans the Downloads folder for new DLL files and alerts on creation: 
    $watcher = New-Object System.IO.FileSystemWatcher
$watcher.Path = "$env:USERPROFILE\Downloads"
$watcher.Filter = ".dll"
$watcher.EnableRaisingEvents = $true
Register-ObjectEvent $watcher "Created" -Action {
Write-Host "DLL created in Downloads: $($Event.SourceEventArgs.FullPath)"
Send alert to SIEM or logging system
}
  4. Enable Windows Defender Application Control (WDAC): Implement WDAC policies to restrict which DLLs can be loaded by the Docker installer. Create a policy that only allows DLLs from `C:\Windows\System32` and `C:\Program Files\Docker` to be loaded.

5. Remediation and Mitigation Best Practices

The most effective mitigation is to upgrade to Docker Desktop version 4.49.0 or later. For organizations that cannot immediately upgrade, several interim measures can reduce the risk:

  • Restrict Write Access to Downloads: Implement Group Policy to prevent standard users from writing DLL files to the Downloads folder. However, this is not a foolproof solution as users often need to write files there.
  • Application Whitelisting: Use AppLocker or WDAC to block the execution of untrusted DLLs.
  • Principle of Least Privilege: Ensure that users do not run with administrative privileges by default.
  • Regular Auditing: Conduct regular audits of system and user directories for unauthorized DLL files.

Step‑by‑step guide: Upgrading to the Patched Version

  1. Backup Docker Data: Before upgrading, backup important Docker data, including images, containers, and volumes. Use `docker save` for images and `docker export` for containers.
  2. Download the Latest Version: Visit the official Docker website and download Docker Desktop for Windows version 4.49.0 or later.
  3. Uninstall the Vulnerable Version: Go to Settings → Apps → Apps & features, find Docker Desktop, and uninstall it.
  4. Install the New Version: Run the new installer and follow the on-screen instructions.
  5. Verify the Installation: After installation, run `docker version` to confirm the new version.
  6. Restore Data: Restore any backed-up images and containers.

6. Linux and Cross-Platform Considerations

While CVE-2025-9164 specifically affects the Windows installer, the broader issue of uncontrolled search paths is relevant across platforms. On Linux, similar vulnerabilities can arise from insecure `LD_LIBRARY_PATH` or `RPATH` settings. Security researchers and system administrators should be aware of these risks and apply consistent hardening principles across all operating systems.

Step‑by‑step guide: Hardening Linux Against Similar DLL/Library Hijacking

  1. Audit RPATH and RUNPATH: Use `readelf -d | grep -E “RPATH|RUNPATH”` to check for insecure library search paths in binaries.
  2. Review LD_LIBRARY_PATH: Ensure that `LD_LIBRARY_PATH` is not set globally or insecurely. Check with echo $LD_LIBRARY_PATH.
  3. Use Secure Loading Practices: When developing applications, use absolute paths for library loading or set `DT_RUNPATH` to a trusted directory.
  4. Monitor Library Loads: Use `strace` or `auditd` to monitor which libraries are being loaded by critical processes.

  5. The Bigger Picture – Secure Coding and Supply Chain Security

The discovery of CVE-2025-9164 highlights the importance of secure coding practices and thorough testing of installer binaries. Developers must ensure that search paths are properly controlled and that untrusted directories are never prioritized over system directories. This vulnerability also underscores the need for robust supply chain security, as compromised installers can lead to widespread system compromises. Organizations should adopt a “secure by default” mindset and conduct regular security reviews of all software deployment processes.

What Undercode Say:

  • Key Takeaway 1: CVE-2025-9164 is a classic DLL hijacking vulnerability that exploits an insecure search path in Docker Desktop Installer.exe, allowing local privilege escalation with a CVSS score of 8.8 (High). The attack is local, requires low privileges, and can lead to full system compromise.

  • Key Takeaway 2: The vulnerability affects all Docker Desktop for Windows versions up to 4.48.0 and has been patched in version 4.49.0. Organizations must prioritize upgrading to the patched version and implement monitoring and access controls to detect and prevent exploitation.

  • Analysis: This vulnerability serves as a critical reminder that even widely used, trusted software can contain fundamental design flaws. The fact that the installer searches the Downloads folder—a directory inherently under user control—before system directories is a glaring oversight that violates basic security principles. While the attack requires local access, the prevalence of Docker Desktop in development and enterprise environments makes this a high-priority issue. The attacker does not need to be an administrator to place the malicious DLL; they only need to write to the Downloads folder, which is typically writable by all users. This lowers the barrier to exploitation significantly. Moreover, the vulnerability’s impact extends beyond privilege escalation—it can serve as a stepping stone for lateral movement, data exfiltration, and persistent backdoor installation. The rapid response from Docker in releasing a patch is commendable, but organizations must also consider long-term architectural improvements, such as implementing application whitelisting and enforcing strict search path controls. The discovery by Mahmoud NourEldin highlights the invaluable role of independent security researchers in identifying and responsibly disclosing vulnerabilities that protect the broader community.

Prediction:

  • +1 The prompt patching of this vulnerability by Docker demonstrates a maturing security culture within the container ecosystem, which will likely encourage other vendors to prioritize similar fixes in their installers, leading to overall improvements in software supply chain security.

  • -1 However, given the simplicity of DLL hijacking attacks and the widespread use of similar insecure search patterns in other Windows applications, it is highly probable that additional vulnerabilities of this nature will be discovered in other popular software, leading to a wave of similar disclosures and potential zero-day exploits in the coming months.

  • -1 The ease of exploitation and the high privileges obtained mean that threat actors will quickly incorporate this technique into their toolkits, especially in targeted attacks against development environments where Docker Desktop is prevalent, increasing the risk of supply chain compromises.

  • +1 Increased awareness of CWE-427 and similar issues will drive the adoption of secure coding guidelines and automated scanning tools that detect uncontrolled search paths, ultimately reducing the prevalence of such vulnerabilities in new software releases.

  • -1 Organizations that delay patching will remain exposed, and because the vulnerability is now publicly documented, attackers will actively scan for unpatched systems, making timely remediation critical to avoid breaches.

▶️ Related Video (76% Match):

https://www.youtube.com/watch?v=8J9TcqxZxdw

🎯Let’s Practice For Free:

🎓 Live Courses & Certifications:

Join Undercode Academy for Verified Certifications

🚀 Request a Custom Project:

Secure, high-velocity infrastructure and disruptive technological engineering. Contact our engineering team for high-tier development and proprietary systems:
[email protected]
💎 Smart Architecture | 🛡️ Secure by Design | ⭐ Trusted by Thousands

IT/Security Reporter URL:

Reported By: Nureldin Ive – Hackers Feeds
Extra Hub: Undercode MoN
Basic Verification: Pass ✅

🔐JOIN OUR CYBER WORLD [ CVE News • HackMonitor • UndercodeNews ]

💬 Whatsapp | 💬 Telegram

📢 Follow UndercodeTesting & Stay Tuned:

𝕏 formerly Twitter 🐦 | @ Threads | 🔗 Linkedin | 🦋BlueSky

Related Posts: