github - ghsa-7cc9-j4mv-vcjp

GHSA-7CC9-J4MV-VCJP

Vulnerability from github – Published: 2024-11-18 20:01 – Updated: 2025-03-06 18:22

Summary

XXE in PHPSpreadsheet's XLSX reader

Details

Summary

The XmlScanner class has a scan method which should prevent XXE attacks.

However, we found another bypass than the previously reported CVE-2024-47873, the regexes from the findCharSet method, which is used for determining the current encoding can be bypassed by using a payload in the encoding UTF-7, and adding at end of the file a comment with the value encoding="UTF-8" with ", which is matched by the first regex, so that encoding='UTF-7' with single quotes ' in the XML header is not matched by the second regex:

 $patterns = [
            '/encoding\\s*=\\s*"([^"]*]?)"/',
            "/encoding\\s*=\\s*'([^']*?)'/",
        ];

A payload for the workbook.xml file can for example be created with CyberChef&input=Pz4KPCFET0NUWVBFIGZvbyBbCiAgPCFFTEVNRU5UIGZvbyBBTlkgPgogIDwhRU5USVRZIHh4ZSBTWVNURU0gImZpbGU6Ly8vZXRjL3Bhc3N3ZCIgPl0%2BCjxmb28%2BJnh4ZTs8L2Zvbz4K). If you open an Excel file containing the payload from the link above stored in the workbook.xml file with PhpSpreadsheet, you will receive an HTTP request on 127.0.0.1:12345. You can test that an HTTP request is created by running the nc -nlvp 12345 command before opening the file containing the payload with PhpSpreadsheet.

To create the payload you need: 1. Create a file containing <?xml version = "1.0" encoding='UTF-7' in an XML file 2. Use the link attached above to create your XXE payload and add it to the XML file. 3. Add +ADw-+ACE---encoding="UTF-8"--+AD4- to the end of the XML file, which is matched by the first regex.

PoC

payload.xlsx

Create a new folder.
Run the composer require phpoffice/phpspreadsheet command in the new folder.
Create an index.php file in that folder with the following content:

<?php
require 'vendor/autoload.php';

use PhpOffice\PhpSpreadsheet\Spreadsheet;
use PhpOffice\PhpSpreadsheet\Writer\Xlsx;

$spreadsheet = new Spreadsheet();

$inputFileType = 'Xlsx';
$inputFileName = './payload.xlsx';

/**  Create a new Reader of the type defined in $inputFileType  **/
$reader = \PhpOffice\PhpSpreadsheet\IOFactory::createReader($inputFileType);
/**  Advise the Reader that we only want to load cell data  **/
$reader->setReadDataOnly(true);

$worksheetData = $reader->listWorksheetInfo($inputFileName);

foreach ($worksheetData as $worksheet) {

$sheetName = $worksheet['worksheetName'];

echo "<h4>$sheetName</h4>";
/**  Load $inputFileName to a Spreadsheet Object  **/
$reader->setLoadSheetsOnly($sheetName);
$spreadsheet = $reader->load($inputFileName);

$worksheet = $spreadsheet->getActiveSheet();
print_r($worksheet->toArray());

}

Run the following command: php -S 127.0.0.1:8080
Add the payload.xlsx file in the folder and open https://127.0.0.1:8080 in a browser. You will see an HTTP request on netcat http://127.0.0.1:12345/ext.dtd.

Impact

An attacker can bypass the sanitizer and achieve an XXE attack.

Severity ?

7.5 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "phpoffice/phpspreadsheet"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.29.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "phpoffice/phpspreadsheet"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.0.0"
            },
            {
              "fixed": "2.1.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "phpoffice/phpspreadsheet"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.2.0"
            },
            {
              "fixed": "2.3.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "phpoffice/phpspreadsheet"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "3.3.0"
            },
            {
              "fixed": "3.4.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Packagist",
        "name": "phpoffice/phpexcel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "1.8.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2024-48917"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-611"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2024-11-18T20:01:46Z",
    "nvd_published_at": "2024-11-18T20:15:05Z",
    "severity": "HIGH"
  },
  "details": "### Summary\n\nThe [XmlScanner class](https://github.com/PHPOffice/PhpSpreadsheet/blob/39fc51309181e82593b06e2fa8e45ef8333a0335/src/PhpSpreadsheet/Reader/Security/XmlScanner.php) has a [scan](https://github.com/PHPOffice/PhpSpreadsheet/blob/39fc51309181e82593b06e2fa8e45ef8333a0335/src/PhpSpreadsheet/Reader/Security/XmlScanner.php#L72) method which should prevent XXE attacks.\n\nHowever, we found another bypass than the previously reported `CVE-2024-47873`, the regexes from the [findCharSet](https://github.com/PHPOffice/PhpSpreadsheet/blob/39fc51309181e82593b06e2fa8e45ef8333a0335/src/PhpSpreadsheet/Reader/Security/XmlScanner.php#L51) method, which is used for determining the current encoding can be bypassed by using a payload in the encoding UTF-7, and adding at end of the file a comment with the value `encoding=\"UTF-8\"` with `\"`, which is matched by the first regex, so that `encoding=\u0027UTF-7\u0027` with single quotes `\u0027` in the XML header is not matched by the second regex: \n\n```\n $patterns = [\n            \u0027/encoding\\\\s*=\\\\s*\"([^\"]*]?)\"/\u0027,\n            \"/encoding\\\\s*=\\\\s*\u0027([^\u0027]*?)\u0027/\",\n        ];\n``` \n\nA payload for the `workbook.xml` file can for example be created with [CyberChef](https://gchq.github.io/CyberChef/#recipe=Encode_text(\u0027UTF-7%20(65000)\u0027)\u0026input=Pz4KPCFET0NUWVBFIGZvbyBbCiAgPCFFTEVNRU5UIGZvbyBBTlkgPgogIDwhRU5USVRZIHh4ZSBTWVNURU0gImZpbGU6Ly8vZXRjL3Bhc3N3ZCIgPl0%2BCjxmb28%2BJnh4ZTs8L2Zvbz4K).\nIf you open an Excel file containing the payload from the link above stored in the `workbook.xml` file with PhpSpreadsheet, you will receive an HTTP request on `127.0.0.1:12345`. You can test that an HTTP request is created by running the `nc -nlvp 12345` command before opening the file containing the payload with PhpSpreadsheet.\n\nTo create the payload you need:\n1. Create a file containing `\u003c?xml version = \"1.0\" encoding=\u0027UTF-7\u0027` in an XML file\n2. Use the link attached above to create your XXE payload and add it to the XML file. \n3. Add `+ADw-+ACE---encoding=\"UTF-8\"--+AD4-` to the end of the XML file, which is matched by the first regex. \n\n### PoC\n\n[payload.xlsx](https://github.com/user-attachments/files/17375792/payload.xlsx)\n\n- Create a new folder.\n- Run the `composer require phpoffice/phpspreadsheet` command in the new folder.\n- Create an `index.php` file in that folder with the following content:\n```PHP\n\u003c?php\nrequire \u0027vendor/autoload.php\u0027;\n\nuse PhpOffice\\PhpSpreadsheet\\Spreadsheet;\nuse PhpOffice\\PhpSpreadsheet\\Writer\\Xlsx;\n\n$spreadsheet = new Spreadsheet();\n\n$inputFileType = \u0027Xlsx\u0027;\n$inputFileName = \u0027./payload.xlsx\u0027;\n\n/**  Create a new Reader of the type defined in $inputFileType  **/\n$reader = \\PhpOffice\\PhpSpreadsheet\\IOFactory::createReader($inputFileType);\n/**  Advise the Reader that we only want to load cell data  **/\n$reader-\u003esetReadDataOnly(true);\n\n$worksheetData = $reader-\u003elistWorksheetInfo($inputFileName);\n\nforeach ($worksheetData as $worksheet) {\n\n$sheetName = $worksheet[\u0027worksheetName\u0027];\n\necho \"\u003ch4\u003e$sheetName\u003c/h4\u003e\";\n/**  Load $inputFileName to a Spreadsheet Object  **/\n$reader-\u003esetLoadSheetsOnly($sheetName);\n$spreadsheet = $reader-\u003eload($inputFileName);\n\n$worksheet = $spreadsheet-\u003egetActiveSheet();\nprint_r($worksheet-\u003etoArray());\n\n}\n```\n- Run the following command: `php -S 127.0.0.1:8080`\n- Add the [payload.xlsx](https://github.com/user-attachments/files/17375792/payload.xlsx) file in the folder and open \u003chttps://127.0.0.1:8080\u003e in a browser. You will see an HTTP request on netcat \u003chttp://127.0.0.1:12345/ext.dtd\u003e.\n\n### Impact\n\nAn attacker can bypass the sanitizer and achieve an [XXE attack](https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing).",
  "id": "GHSA-7cc9-j4mv-vcjp",
  "modified": "2025-03-06T18:22:21Z",
  "published": "2024-11-18T20:01:46Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-7cc9-j4mv-vcjp"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-48917"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/PHPOffice/PhpSpreadsheet"
    },
    {
      "type": "WEB",
      "url": "https://github.com/PHPOffice/PhpSpreadsheet/blob/39fc51309181e82593b06e2fa8e45ef8333a0335/src/PhpSpreadsheet/Reader/Security/XmlScanner.php"
    },
    {
      "type": "WEB",
      "url": "https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "XXE in PHPSpreadsheet\u0027s XLSX reader"
}

CVE-2024-48917 (GCVE-0-2024-48917)

Vulnerability from cvelistv5 – Published: 2024-11-18 19:48 – Updated: 2024-11-18 20:15

Summary

PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. The `XmlScanner` class has a scan method which should prevent XXE attacks. However, in a bypass of the previously reported `CVE-2024-47873`, the regexes from the `findCharSet` method, which is used for determining the current encoding can be bypassed by using a payload in the encoding UTF-7, and adding at end of the file a comment with the value `encoding="UTF-8"` with `"`, which is matched by the first regex, so that `encoding='UTF-7'` with single quotes `'` in the XML header is not matched by the second regex. An attacker can bypass the sanitizer and achieve an XML external entity attack. Versions 1.9.4, 2.1.3, 2.3.2, and 3.4.0 fix the issue.

Severity ?

7.5 (High)


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

CWE

CWE-611 - Improper Restriction of XML External Entity Reference

Assigner

GitHub_M

References

URL

Tags

	https://github.com/PHPOffice/PhpSpreadsheet/secur…	x_refsource_CONFIRM
	https://github.com/PHPOffice/PhpSpreadsheet/blob/…	x_refsource_MISC
	https://owasp.org/www-community/vulnerabilities/X…	x_refsource_MISC

Impacted products

	Vendor	Product	Version
	PHPOffice	PhpSpreadsheet	Affected: < 1.29.4 Affected: >= 2.0.0, < 2.1.3 Affected: >= 2.2.0, < 2.3.2 Affected: >= 3.3.0, < 3.4.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "affected": [
          {
            "cpes": [
              "cpe:2.3:a:phpoffice:phpspreadsheet:-:*:*:*:*:*:*:*"
            ],
            "defaultStatus": "unknown",
            "product": "phpspreadsheet",
            "vendor": "phpoffice",
            "versions": [
              {
                "lessThan": "1.29.4",
                "status": "affected",
                "version": "0",
                "versionType": "custom"
              },
              {
                "lessThan": "2.1.3",
                "status": "affected",
                "version": "2.0.0",
                "versionType": "custom"
              },
              {
                "lessThan": "2.3.2",
                "status": "affected",
                "version": "2.2.0",
                "versionType": "custom"
              },
              {
                "lessThan": "3.4.0",
                "status": "affected",
                "version": "3.3.0",
                "versionType": "custom"
              }
            ]
          }
        ],
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2024-48917",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-11-18T20:14:30.431041Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-11-18T20:15:55.299Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "PhpSpreadsheet",
          "vendor": "PHPOffice",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 1.29.4"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.0.0, \u003c 2.1.3"
            },
            {
              "status": "affected",
              "version": "\u003e= 2.2.0, \u003c 2.3.2"
            },
            {
              "status": "affected",
              "version": "\u003e= 3.3.0, \u003c 3.4.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "PhpSpreadsheet is a PHP library for reading and writing spreadsheet files. The `XmlScanner` class has a scan method which should prevent XXE attacks. However, in a bypass of the previously reported `CVE-2024-47873`, the regexes from the `findCharSet` method, which is used for determining the current encoding can be bypassed by using a payload in the encoding UTF-7, and adding at end of the file a comment with the value `encoding=\"UTF-8\"` with `\"`, which is matched by the first regex, so that `encoding=\u0027UTF-7\u0027` with single quotes `\u0027` in the XML header is not matched by the second regex. An attacker can bypass the sanitizer and achieve an XML external entity attack. Versions 1.9.4, 2.1.3, 2.3.2, and 3.4.0 fix the issue."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.5,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-611",
              "description": "CWE-611: Improper Restriction of XML External Entity Reference",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2024-11-18T19:48:42.656Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-7cc9-j4mv-vcjp",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/PHPOffice/PhpSpreadsheet/security/advisories/GHSA-7cc9-j4mv-vcjp"
        },
        {
          "name": "https://github.com/PHPOffice/PhpSpreadsheet/blob/39fc51309181e82593b06e2fa8e45ef8333a0335/src/PhpSpreadsheet/Reader/Security/XmlScanner.php",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/PHPOffice/PhpSpreadsheet/blob/39fc51309181e82593b06e2fa8e45ef8333a0335/src/PhpSpreadsheet/Reader/Security/XmlScanner.php"
        },
        {
          "name": "https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://owasp.org/www-community/vulnerabilities/XML_External_Entity_(XXE)_Processing"
        }
      ],
      "source": {
        "advisory": "GHSA-7cc9-j4mv-vcjp",
        "discovery": "UNKNOWN"
      },
      "title": "XXE in PHPSpreadsheet\u0027s XLSX reader"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2024-48917",
    "datePublished": "2024-11-18T19:48:42.656Z",
    "dateReserved": "2024-10-09T22:06:46.172Z",
    "dateUpdated": "2024-11-18T20:15:55.299Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

Sightings

Author	Source	Type	Date

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.

Action not permitted

GHSA-7CC9-J4MV-VCJP

Summary

PoC

Impact

CVE-2024-48917 (GCVE-0-2024-48917)

Tags

Sightings

Nomenclature