Vulnerability-Lookup

CVE-2026-25524 (GCVE-0-2026-25524)

Vulnerability from cvelistv5 – Published: 2026-04-20 16:11 – Updated: 2026-04-20 16:54

Title

OpenMage LTS's Phar Deserialization leads to Remote Code Execution

Summary

Magento Long Term Support (LTS) is an unofficial, community-driven project provides an alternative to the Magento Community Edition e-commerce platform with a high level of backward compatibility. Prior to version 20.17.0, PHP functions such as `getimagesize()`, `file_exists()`, and `is_readable()` can trigger deserialization when processing `phar://` stream wrapper paths. OpenMage LTS uses these functions with potentially controllable file paths during image validation and media handling. An attacker who can upload a malicious phar file (disguised as an image) and trigger one of these functions with a `phar://` path can achieve arbitrary code execution. Version 20.17.0 patches the issue.

Severity

8.1 (High)


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

SSVC

Exploitation: poc Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-04-20 16:44 UTC

CWE

CWE-502 - Deserialization of Untrusted Data

Assigner

GitHub_M mitre root

References

2 references

URL	Tags
https://github.com/OpenMage/magento-lts/security/…	x_refsource_CONFIRM
https://github.com/OpenMage/magento-lts/releases/…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version	CPE status
OpenMage	magento-lts	Affected: < 20.17.0	guessed

Show details on NVD website

JSON

To clipboard

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FKIE_CVE-2026-25524

Vulnerability from fkie_nvd - Published: 2026-04-20 17:16 - Updated: 2026-06-17 10:24

Severity

8.1 (High) - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

Summary

References

	URL	Tags
	security-advisories@github.com	https://github.com/OpenMage/magento-lts/releases/tag/v20.17.0	Release Notes
	security-advisories@github.com	https://github.com/OpenMage/magento-lts/security/advisories/GHSA-fg79-cr9c-7369	Exploit, Mitigation, Vendor Advisory

Impacted products

	Vendor	Product	Version
	openmage	magento	*

JSON

To clipboard

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          "product": "magento-lts",
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GHSA-FG79-CR9C-7369

Vulnerability from github – Published: 2026-04-21 14:32 – Updated: 2026-04-21 14:32

Summary

OpenMage LTS: Phar Deserialization leads to Remote Code Execution

Details

PHP functions such as getimagesize(), file_exists(), and is_readable() can trigger deserialization when processing phar:// stream wrapper paths. OpenMage LTS uses these functions with potentially controllable file paths during image validation and media handling. An attacker who can upload a malicious phar file (disguised as an image) and trigger one of these functions with a phar:// path can achieve arbitrary code execution.

Metric	Value	Justification
Attack Vector (AV)	Network	Exploitable via file upload and web requests
Attack Complexity (AC)	High	Requires file upload + triggering phar:// access
Privileges Required (PR)	None	Some upload vectors don't require authentication
User Interaction (UI)	None	Exploitation is automatic once triggered
Scope (S)	Unchanged	Impacts the vulnerable component
Confidentiality (C)	High	Full system access via RCE
Integrity (I)	High	Arbitrary code execution
Availability (A)	High	Complete system compromise possible

Affected Products

OpenMage LTS versions < 20.16.1
All versions derived from Magento 1.x with these code paths

Affected Files

File	Line	Vulnerable Function
`app/code/core/Mage/Core/Model/File/Validator/Image.php`	72	`getimagesize($filePath)`
`app/code/core/Mage/Cms/Model/Wysiwyg/Images/Storage.php`	137	`getimagesize($item->getFilename())`
`lib/Varien/Image.php`	71	`$this->_getAdapter()->open($this->_fileName)`

Vulnerability Details

PHP's phar (PHP Archive) format stores metadata that is serialized. When PHP's stream wrapper functions access a file using the phar:// protocol, the metadata is automatically deserialized. This occurs even with seemingly safe functions like file_exists() or getimagesize().

A polyglot file can be crafted that is both a valid image (passing initial validation) and a valid phar archive containing malicious serialized objects. When the application later processes this file using phar://, the deserialization triggers a gadget chain leading to RCE.

Attack Flow

Create polyglot file: Attacker creates a file that is both valid JPEG and valid PHAR
Upload file: Attacker uploads the polyglot via product images, CMS media, or import
Trigger phar:// access: Attacker causes the application to access the file using phar:// wrapper
Code execution: PHAR metadata deserialization triggers gadget chain

Proof of Concept

<?php
// Create malicious phar file
class ExploitGadget {
    public $cmd = 'id > /tmp/pwned';
    function __destruct() {
        system($this->cmd);
    }
}

$phar = new Phar('exploit.phar');
$phar->startBuffering();
$phar->addFromString('test.txt', 'test');
$phar->setStub('<?php __HALT_COMPILER(); ?>');
$phar->setMetadata(new ExploitGadget());
$phar->stopBuffering();

// Rename to appear as image
rename('exploit.phar', 'exploit.jpg');

// When getimagesize('phar://path/to/exploit.jpg') is called,
// the ExploitGadget::__destruct() method executes

Remediation

Block phar:// paths before passing to vulnerable functions:

// Before (vulnerable)
[$imageWidth, $imageHeight, $fileType] = getimagesize($filePath);

// After (fixed)
if (str_starts_with($filePath, 'phar://')) {
    throw new Exception('Invalid image path.');
}
[$imageWidth, $imageHeight, $fileType] = getimagesize($filePath);

Additionally, ICO files (which cannot be re-encoded by GD) are now scanned for phar signatures:

__HALT_COMPILER(); - Required phar stub
<?php - PHP opening tag
<?= - PHP short echo tag

Additional hardening measures:

ICO uploads removed: ICO file support is completely removed from new image uploads. This eliminates the polyglot attack vector entirely since all other image formats are re-encoded by GD, which strips any embedded phar metadata.
Phar wrapper disabled: The phar:// stream wrapper is unregistered at application bootstrap, preventing any phar deserialization attacks regardless of code path.
Cache deserialization hardening: All unserialize() calls on cached data now use allowed_classes => false as defense-in-depth.

Note: Existing uploaded ICO files will continue to work. Only new ICO uploads will be rejected. Users are encouraged to use PNG favicons for new uploads.

Workarounds

If immediate upgrade is not possible:

Disable phar stream wrapper (if not needed):

ini ; php.ini disable_functions = phar://

Or in code:

php stream_wrapper_unregister('phar');

Strict upload validation: Implement additional validation beyond file extension
File storage isolation: Store uploads outside web root with randomized names
Web Application Firewall: Block requests containing phar:// in parameters

Credit

This vulnerability was discovered and responsibly disclosed by blackhat2013 through HackerOne.

Timeline

2025-12-31: Vulnerability reported via HackerOne
2026-01-21: Fix developed and tested

Source: https://hackerone.com/reports/3482926

Severity

8.1 (High)


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

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "openmage/magento-lts"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "20.17.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-25524"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-502"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-21T14:32:48Z",
    "nvd_published_at": "2026-04-20T17:16:32Z",
    "severity": "HIGH"
  },
  "details": "PHP functions such as `getimagesize()`, `file_exists()`, and `is_readable()` can trigger deserialization when processing `phar://` stream wrapper paths. OpenMage LTS uses these functions with potentially controllable file paths during image validation and media handling. An attacker who can upload a malicious phar file (disguised as an image) and trigger one of these functions with a `phar://` path can achieve arbitrary code execution.\n\n| Metric                   | Value     | Justification                                    |\n| ------------------------ | --------- | ------------------------------------------------ |\n| Attack Vector (AV)       | Network   | Exploitable via file upload and web requests     |\n| Attack Complexity (AC)   | High      | Requires file upload + triggering phar:// access |\n| Privileges Required (PR) | None      | Some upload vectors don\u0027t require authentication |\n| User Interaction (UI)    | None      | Exploitation is automatic once triggered         |\n| Scope (S)                | Unchanged | Impacts the vulnerable component                 |\n| Confidentiality (C)      | High      | Full system access via RCE                       |\n| Integrity (I)            | High      | Arbitrary code execution                         |\n| Availability (A)         | High      | Complete system compromise possible              |\n\n## Affected Products\n\n- OpenMage LTS versions \u003c 20.16.1\n- All versions derived from Magento 1.x with these code paths\n\n## Affected Files\n\n| File                                                      | Line | Vulnerable Function                            |\n| --------------------------------------------------------- | ---- | ---------------------------------------------- |\n| `app/code/core/Mage/Core/Model/File/Validator/Image.php`  | 72   | `getimagesize($filePath)`                      |\n| `app/code/core/Mage/Cms/Model/Wysiwyg/Images/Storage.php` | 137  | `getimagesize($item-\u003egetFilename())`           |\n| `lib/Varien/Image.php`                                    | 71   | `$this-\u003e_getAdapter()-\u003eopen($this-\u003e_fileName)` |\n\n## Vulnerability Details\n\nPHP\u0027s phar (PHP Archive) format stores metadata that is serialized. When PHP\u0027s stream wrapper functions access a file using the `phar://` protocol, the metadata is automatically deserialized. This occurs even with seemingly safe functions like `file_exists()` or `getimagesize()`.\n\nA polyglot file can be crafted that is both a valid image (passing initial validation) and a valid phar archive containing malicious serialized objects. When the application later processes this file using `phar://`, the deserialization triggers a gadget chain leading to RCE.\n\n### Attack Flow\n\n1. **Create polyglot file**: Attacker creates a file that is both valid JPEG and valid PHAR\n2. **Upload file**: Attacker uploads the polyglot via product images, CMS media, or import\n3. **Trigger phar:// access**: Attacker causes the application to access the file using `phar://` wrapper\n4. **Code execution**: PHAR metadata deserialization triggers gadget chain\n\n### Proof of Concept\n\n```php\n\u003c?php\n// Create malicious phar file\nclass ExploitGadget {\n    public $cmd = \u0027id \u003e /tmp/pwned\u0027;\n    function __destruct() {\n        system($this-\u003ecmd);\n    }\n}\n\n$phar = new Phar(\u0027exploit.phar\u0027);\n$phar-\u003estartBuffering();\n$phar-\u003eaddFromString(\u0027test.txt\u0027, \u0027test\u0027);\n$phar-\u003esetStub(\u0027\u003c?php __HALT_COMPILER(); ?\u003e\u0027);\n$phar-\u003esetMetadata(new ExploitGadget());\n$phar-\u003estopBuffering();\n\n// Rename to appear as image\nrename(\u0027exploit.phar\u0027, \u0027exploit.jpg\u0027);\n\n// When getimagesize(\u0027phar://path/to/exploit.jpg\u0027) is called,\n// the ExploitGadget::__destruct() method executes\n```\n\n## Remediation\n\nBlock `phar://` paths before passing to vulnerable functions:\n\n```php\n// Before (vulnerable)\n[$imageWidth, $imageHeight, $fileType] = getimagesize($filePath);\n\n// After (fixed)\nif (str_starts_with($filePath, \u0027phar://\u0027)) {\n    throw new Exception(\u0027Invalid image path.\u0027);\n}\n[$imageWidth, $imageHeight, $fileType] = getimagesize($filePath);\n```\n\nAdditionally, ICO files (which cannot be re-encoded by GD) are now scanned for phar signatures:\n\n- `__HALT_COMPILER();` - Required phar stub\n- `\u003c?php` - PHP opening tag\n- `\u003c?=` - PHP short echo tag\n\nAdditional hardening measures:\n\n1. **ICO uploads removed**: ICO file support is completely removed from new image uploads. This eliminates the polyglot attack vector entirely since all other image formats are re-encoded by GD, which strips any embedded phar metadata.\n\n2. **Phar wrapper disabled**: The `phar://` stream wrapper is unregistered at application bootstrap, preventing any phar deserialization attacks regardless of code path.\n\n3. **Cache deserialization hardening**: All `unserialize()` calls on cached data now use `allowed_classes =\u003e false` as defense-in-depth.\n\n**Note:** Existing uploaded ICO files will continue to work. Only new ICO uploads will be rejected. Users are encouraged to use PNG favicons for new uploads.\n\n## Workarounds\n\nIf immediate upgrade is not possible:\n\n1. **Disable phar stream wrapper** (if not needed):\n\n   ```ini\n   ; php.ini\n   disable_functions = phar://\n   ```\n\n   Or in code:\n\n   ```php\n   stream_wrapper_unregister(\u0027phar\u0027);\n   ```\n\n2. **Strict upload validation**: Implement additional validation beyond file extension\n\n3. **File storage isolation**: Store uploads outside web root with randomized names\n\n4. **Web Application Firewall**: Block requests containing `phar://` in parameters\n\n\n## Credit\n\nThis vulnerability was discovered and responsibly disclosed by [blackhat2013](https://hackerone.com/blackhat2013) through HackerOne.\n\n## Timeline\n\n- **2025-12-31**: Vulnerability reported via HackerOne\n- **2026-01-21**: Fix developed and tested\n\nSource: https://hackerone.com/reports/3482926",
  "id": "GHSA-fg79-cr9c-7369",
  "modified": "2026-04-21T14:32:48Z",
  "published": "2026-04-21T14:32:48Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/OpenMage/magento-lts/security/advisories/GHSA-fg79-cr9c-7369"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-25524"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/OpenMage/magento-lts"
    },
    {
      "type": "WEB",
      "url": "https://github.com/OpenMage/magento-lts/releases/tag/v20.17.0"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "OpenMage LTS: Phar Deserialization leads to Remote Code Execution"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

CVE-2026-25524 (GCVE-0-2026-25524)

FKIE_CVE-2026-25524

GHSA-FG79-CR9C-7369

Affected Products

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Vulnerability Details

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