T05 · Unauthorized Access and Privilege Escalation
Error
- Location
- scripts/main.py:48
- Finding
- Unrestricted Access to Internal, Private, and Cloud Metadata Endpoints<![CDATA[ ## Vulnerability Details **File Location**: `scripts/main.py:48-58`, `scripts/main.py:124-131` **Vulnerability Type**: Server-Side Request Forgery and unrestricted network access **Risk Level**: High ### Vulnerable Code ```python response = requests.request( method=method, url=url, headers=request_headers, json=json_data, data=data, timeout=timeout, verify=verify_ssl, allow_redirects=allow_redirects ) ``` ```python # Validate URL format if not args.url.startswith(("http://", "https://")): return { "status": "error", "error_message": "URL must start with http:// or https://" } ``` ### Technical Analysis The URL validation only checks whether the supplied string begins with `http://` or `https://`. It does not restrict the destination hostname or resolved IP address. Consequently, the requester can target: - Loopback addresses such as `127.0.0.1` and `::1` - Private network ranges - Link-local services - Cloud metadata endpoints such as `169.254.169.254` - Internal hostnames resolved by the host's DNS infrastructure - Public URLs that redirect to internal destinations Redirect following is enabled by default, and no validation is performed for redirect targets. The tool also accepts attacker-controlled HTTP methods, headers, and bodies, allowing both read and state-changing requests against reachable internal services. Although arbitrary API testing is part of the declared functionality, unrestricted access to infrastructure-only destinations violates least-privilege principles when invocation arguments can be influenced by untrusted content. ### Attack Path 1. An attacker influences the URL and related arguments passed to the Skill. 2. The attacker supplies a loopback, private-network, link-local, or cloud metadata URL. Alternatively, the attacker provides a public URL that redirects to an internal service. 3. The process sends the request from the Agent host's network context. 4. The ...[truncated 980 chars]
- Remediation
- <![CDATA[ ## Remediation Suggestions 1. Parse URLs with a standards-compliant URL parser rather than relying on a string-prefix check. 2. Resolve the destination hostname before sending the request. 3. Reject loopback, private, link-local, multicast, reserved, and unspecified IPv4 and IPv6 addresses by default. 4. Explicitly block cloud metadata endpoints and relevant metadata hostnames. 5. Re-resolve and revalidate every redirect destination before following it. 6. Protect against DNS rebinding by ensuring the connection is made only to an address that was validated. 7. Prefer an explicit hostname or network allowlist for normal operation. 8. If private-network testing is required, place it behind a clearly documented, explicit opt-in and display a security warning. 9. Consider restricting state-changing methods when targeting destinations outside a configured allowlist. ]]>