Token Optimizer MCP: Unauthenticated Path Traversal in Dashboard Session Log API Endpoints

Unauthenticated Path Traversal in Dashboard Session Log API Endpoints

Field Value

Repository ooples/token-optimizer-mcp

Affected version 5.0.1 (commit 8137147)

Vulnerability CWE-22 — Improper Limitation of a Pathname to a Restricted Directory

Severity Medium

CVSS 3.1 5.3 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N)

Summary

The dashboard HTTP server in token-optimizer-mcp exposes /api/session-summary and /api/session-events with no authentication middleware — any network-accessible client can reach them without credentials. Both handlers concatenate the caller-supplied sessionId query parameter directly into a filesystem path via path.join, and Node.js normalizes .. segments at resolution time, allowing an unauthenticated attacker to read any .jsonl file reachable from the server's filesystem. Successful reproduction confirmed exfiltration of a .jsonl file located outside the intended hooksDataPath directory with a single unauthenticated HTTP GET request.

Affected Code

src/server/web-server.ts:73–88 — /api/session-summary: unsanitized sessionId interpolated into path.join then passed to fs.readFileSync

    const hooksDataPath = getHooksDataPath();
    const jsonlFilePath = path.join(
      hooksDataPath,
      `session-log-${sessionId}.jsonl`
    );

    if (!fs.existsSync(jsonlFilePath)) {
      return res.status(404).json({
        success: false,
        error: `JSONL log not found for session ${sessionId}`,
        sessionId,
      });
    }

    // Parse JSONL file
    const jsonlContent = fs.readFileSync(jsonlFilePath, 'utf-8');