ghsa-mqpq-2p68-46fv
Vulnerability from github
Summary
Any unauthenticated user can browse to a specific URL to expose the Flask config, including the SECRET_KEY
variable.
Details
Any unauthenticated user can browse to a specific URL to expose the Flask config, including the SECRET_KEY
variable.
PoC
Run pyload
in the default configuration by running the following command
pyload
Now browse to http://localhost:8000/render/info.html
. Notice how the Flask configuration gets displayed.
I was quite amused by this finding. I think it's a very interesting coming together of things that is so unlikely to happen. Below I will detail my process a bit more.
I was looking through the code to see how the authorization mechanism is implemented when I spotted this route, which can be accessed by any unauthenticated actor
- https://github.com/pyload/pyload/blob/57d81930edb59177c60830ad8ac36a91d0ec4c4e/src/pyload/webui/app/blueprints/app_blueprint.py#L33C1-L37C51
python
@bp.route("/render/<path:filename>", endpoint="render")
def render(filename):
mimetype = mimetypes.guess_type(filename)[0] or "text/html"
data = render_template(filename)
return flask.Response(data, mimetype=mimetype)
This route allows me to load in any of the predefined templates. However, these templates will be lacking any form of context, and as such it doesn't seem too useful. That is until I loaded the info.html
template and scrolled down, revealing the Flask config. This was purely accidental, and I did not understand why it happened, until I looked at the template
- https://github.com/pyload/pyload/blob/57d81930edb59177c60830ad8ac36a91d0ec4c4e/src/pyload/webui/app/templates/info.html#L64C1-L67C10
python <tr> <td>{{ _("Config folder:") }}</td> <td>{{ config }}</td> </tr>
In Flask, every template always gets the Flask config passed to it as the config
variable. In the normal execution of this template, this value gets overwritten in the function below, but since we're calling it and bypassing this function altogether, it doesn't get overwritten. Would this variable not be named config and named configuration
or Config
instead, then this exploit wouldn't work. The likelihood of this occurring is so small, but it seems to have happened here.
- https://github.com/pyload/pyload/blob/57d81930edb59177c60830ad8ac36a91d0ec4c4e/src/pyload/webui/app/blueprints/app_blueprint.py#L450C1-L461C51
python context = { "python": sys.version, "os": " ".join((os.name, sys.platform) + extra), "version": api.get_server_version(), "folder": PKGDIR, "config": api.get_userdir(), "download": conf["general"]["storage_folder"]["value"], "freespace": format.size(api.free_space()), "webif": conf["webui"]["port"]["value"], "language": conf["general"]["language"]["value"], } return render_template("info.html", **context)
Impact
Depending on the how the Flask config data is used, it could have detrimental consequences for the security. It's crucial to keep the SECRET_KEY
secret and never expose it in your code or configuration files.
{ "affected": [ { "package": { "ecosystem": "PyPI", "name": "pyload-ng" }, "ranges": [ { "events": [ { "introduced": "0" }, { "fixed": "0.5.0b3.dev77" } ], "type": "ECOSYSTEM" } ] } ], "aliases": [ "CVE-2024-21644" ], "database_specific": { "cwe_ids": [ "CWE-284" ], "github_reviewed": true, "github_reviewed_at": "2024-01-08T15:40:39Z", "nvd_published_at": "2024-01-08T14:15:47Z", "severity": "HIGH" }, "details": "### Summary\nAny unauthenticated user can browse to a specific URL to expose the Flask config, including the `SECRET_KEY` variable.\n\n### Details\nAny unauthenticated user can browse to a specific URL to expose the Flask config, including the `SECRET_KEY` variable.\n\n### PoC\nRun `pyload` in the default configuration by running the following command\n```\npyload\n```\n\nNow browse to `http://localhost:8000/render/info.html`. Notice how the Flask configuration gets displayed.\n\n\nI was quite amused by this finding. I think it\u0027s a very interesting coming together of things that is so unlikely to happen. Below I will detail my process a bit more.\n\nI was looking through the code to see how the authorization mechanism is implemented when I spotted this route, which can be accessed by any unauthenticated actor\n- https://github.com/pyload/pyload/blob/57d81930edb59177c60830ad8ac36a91d0ec4c4e/src/pyload/webui/app/blueprints/app_blueprint.py#L33C1-L37C51\n```python\n@bp.route(\"/render/\u003cpath:filename\u003e\", endpoint=\"render\")\ndef render(filename):\n mimetype = mimetypes.guess_type(filename)[0] or \"text/html\"\n data = render_template(filename)\n return flask.Response(data, mimetype=mimetype)\n ```\n\nThis route allows me to load in any of the predefined templates. However, these templates will be lacking any form of context, and as such it doesn\u0027t seem too useful. That is until I loaded the `info.html` template and scrolled down, revealing the Flask config. This was purely accidental, and I did not understand why it happened, until I looked at the template\n\n- https://github.com/pyload/pyload/blob/57d81930edb59177c60830ad8ac36a91d0ec4c4e/src/pyload/webui/app/templates/info.html#L64C1-L67C10\n```python\n \u003ctr\u003e\n \u003ctd\u003e{{ _(\"Config folder:\") }}\u003c/td\u003e\n \u003ctd\u003e{{ config }}\u003c/td\u003e\n \u003c/tr\u003e\n```\n\nIn Flask, every template always gets the Flask config passed to it as the `config` variable. In the normal execution of this template, this value gets overwritten in the function below, but since we\u0027re calling it and bypassing this function altogether, it doesn\u0027t get overwritten. Would this variable not be named config and named `configuration` or `Config` instead, then this exploit wouldn\u0027t work. The likelihood of this occurring is so small, but it seems to have happened here.\n\n- https://github.com/pyload/pyload/blob/57d81930edb59177c60830ad8ac36a91d0ec4c4e/src/pyload/webui/app/blueprints/app_blueprint.py#L450C1-L461C51\n```python\n context = {\n \"python\": sys.version,\n \"os\": \" \".join((os.name, sys.platform) + extra),\n \"version\": api.get_server_version(),\n \"folder\": PKGDIR,\n \"config\": api.get_userdir(),\n \"download\": conf[\"general\"][\"storage_folder\"][\"value\"],\n \"freespace\": format.size(api.free_space()),\n \"webif\": conf[\"webui\"][\"port\"][\"value\"],\n \"language\": conf[\"general\"][\"language\"][\"value\"],\n }\n return render_template(\"info.html\", **context)\n ```\n\n### Impact\nDepending on the how the Flask config data is used, it could have detrimental consequences for the security. It\u0027s crucial to keep the `SECRET_KEY` secret and never expose it in your code or configuration files.\n", "id": "GHSA-mqpq-2p68-46fv", "modified": "2024-01-08T15:40:39Z", "published": "2024-01-08T15:40:39Z", "references": [ { "type": "WEB", "url": "https://github.com/pyload/pyload/security/advisories/GHSA-mqpq-2p68-46fv" }, { "type": "ADVISORY", "url": "https://nvd.nist.gov/vuln/detail/CVE-2024-21644" }, { "type": "WEB", "url": "https://github.com/pyload/pyload/commit/bb22063a875ffeca357aaf6e2edcd09705688c40" }, { "type": "PACKAGE", "url": "https://github.com/pyload/pyload" } ], "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": "pyload Unauthenticated Flask Configuration Leakage vulnerability" }
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.