{"id":"CVE-2025-7346","aliases":["PYSEC-2026-1822"],"url":"https://o3.security/vulnerability/CVE-2025-7346","summary":"pyLoad is vulnerable to attacks that bypass localhost restrictions, enabling the creation of arbitrary packages","details":"### Summary\nAny unauthenticated attacker can bypass the localhost restrictions posed by the application and utilize this to create arbitrary packages.\n\n### Details\nAny unauthenticated attacker can bypass the localhost restrictions posed by the application and utilize this to create arbitrary packages. This is done by changing the `Host` header to the value of `127.0.0.1:9666`.\n\n### PoC\nThe application has middleware that prevents access to several routes by checking whether the `Host` header has a specific value. We bypassed this restriction.\n\nhttps://github.com/pyload/pyload/blob/4159a1191ec4fe6d927e57a9c4bb8f54e16c381d/src/pyload/webui/app/blueprints/cnl_blueprint.py#L21-L36\n```python\n#: decorator\ndef local_check(func):\n    @wraps(func)\n    def wrapper(*args, **kwargs):\n        remote_addr = flask.request.environ.get(\"REMOTE_ADDR\", \"0\")\n        http_host = flask.request.environ.get(\"HTTP_HOST\", \"0\")\n\n        if remote_addr in (\"127.0.0.1\", \"::ffff:127.0.0.1\", \"::1\", \"localhost\") or http_host in (\n            \"127.0.0.1:9666\",\n            \"[::1]:9666\",\n        ):\n            return func(*args, **kwargs)\n        else:\n            return \"Forbidden\", 403\n\n    return wrapper\n```\n\nBelow we see that the '/flash/add' endpoint uses the middleware above.\n\nhttps://github.com/pyload/pyload/blob/4159a1191ec4fe6d927e57a9c4bb8f54e16c381d/src/pyload/webui/app/blueprints/cnl_blueprint.py#L56-L58C11\n```python\n@bp.route(\"/flash/add\", methods=[\"POST\"], endpoint=\"add\")\n@local_check\ndef add():\n```\n\nNotice how we are not authorized to access this endpoint when sending a request.\n![image](https://user-images.githubusercontent.com/44903767/294935526-64217d91-c0d1-4d8f-963f-cedfa8dc9034.png)\n\nHowever, if we set the `Host` header to be `127.0.0.1:9666`, we notice the request returns `success`.\n![image](https://user-images.githubusercontent.com/44903767/294933755-43ad3826-0e94-4ba5-acf0-48f11670cbc6.png)\n\nChecking the front end as an admin, we now see that this did indeed succeed.\n![image](https://user-images.githubusercontent.com/44903767/294934431-5d024c75-59dc-47b6-8887-b14ae91e320f.png)\n\n### Impact\nAn unauthenticated user can perform actions that should only be available to authenticated users.","published":"2025-07-08T21:36:52Z","modified":"2026-07-07T17:57:12.347432283Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"PyPI","name":"pyload-ng","fixedVersion":null}],"fix":{"url":"https://github.com/pyload/pyload/commit/f4e2d12416ba2dfac7b036d5c8d6dab5461b9840","label":"pyload/pyload@f4e2d12"},"references":[{"type":"WEB","url":"https://github.com/pyload/pyload/security/advisories/GHSA-x698-5hjm-w2m5"},{"type":"WEB","url":"https://github.com/pyload/pyload/commit/f4e2d12416ba2dfac7b036d5c8d6dab5461b9840"},{"type":"PACKAGE","url":"https://github.com/pyload/pyload"},{"type":"WEB","url":"https://github.com/pyload/pyload/blob/4159a1191ec4fe6d927e57a9c4bb8f54e16c381d/src/pyload/webui/app/blueprints/cnl_blueprint.py#L21-L36"},{"type":"WEB","url":"https://github.com/pyload/pyload/blob/4159a1191ec4fe6d927e57a9c4bb8f54e16c381d/src/pyload/webui/app/blueprints/cnl_blueprint.py#L56-L58C11"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-07-07T17:57:12.347432283Z"}}