{"id":"GHSA-39wr-7q6h-cf68","aliases":[],"url":"https://o3.security/vulnerability/GHSA-39wr-7q6h-cf68","summary":"LMDeploy has an SSRF bypass","details":"### Summary\nThe URL checking logic in lmdeploy has a logical flaw that could be bypassed by attackers, leading to SSRF attacks.\n\n### Details\nThe current lmdeploy project uses `_is_safe_url` to validate the input URL. The main logic is to perform security checks on the host portion of the URL extracted by urlparse to prevent SSRF attacks.\n<img width=\"943\" height=\"836\" alt=\"QQ20260416-203956-16-1\" src=\"https://github.com/user-attachments/assets/042faad1-7458-444a-bbc9-525c772b0a4d\" />\nHowever, there are indeed differences in parsing between urlparse and the library that actually sends the request. Currently, almost all application scenarios in this project involve first using `_is_safe_url` for URL validation, and then using requests.Session().get to send the request.\n<img width=\"1086\" height=\"576\" alt=\"QQ20260416-204053-16-2\" src=\"https://github.com/user-attachments/assets/7ffb8a69-b155-483a-90be-016c53e6387a\" />\nThe core issue: `urlparse()` and `requests` disagree on which host a URL like `http://127.0.0.1:6666\\@1.1.1.1` points to:\n\n- `urlparse()` treats `\\` as a regular character and `@` as the userinfo-host delimiter, so it extracts hostname as 1.1.1.1 (public)\n- `requests` treats `\\` as a path character, connecting to `127.0.0.1` (internal)\n\nBelow is a test code I wrote following the code.\n```\nfrom urllib.parse import urlparse\nimport ipaddress\nimport socket\nimport requests\n\n\ndef _is_safe_url(url: str) -> tuple[bool, str]:\n    \"\"\"Check if the URL is safe to fetch (not internal/private).\"\"\"\n    try:\n        parsed = urlparse(url)\n        if parsed.scheme not in (\"http\", \"https\"):\n            return False, f\"Unsupported scheme: {parsed.scheme}\"\n\n        hostname = parsed.hostname\n        if not hostname:\n            return False, \"Could not parse hostname from URL\"\n\n        # check all IPs (IPv4 + IPv6) using getaddrinfo\n        try:\n            infos = socket.getaddrinfo(hostname, None)\n        except socket.gaierror:\n            return False, \"Hostname resolution failed\"\n\n        for info in infos:\n            ip = ipaddress.ip_address(info[4][0])\n            # block any IP that is not globally routable (covers private, loopback,\n            # link-local, multicast, reserved, unspecified, etc.)\n            if not ip.is_global:\n                return False, f\"Blocked non-global IP detected: {ip}\"\n\n        return True, \"URL is safe\"\n    except Exception as e:\n        return False, f\"URL validation failed: {str(e)}\"\n\n\n# url = \"http://127.0.0.1:6666\"\nurl = \"http://127.0.0.1:6666\\@1.1.1.1\"\nis_safe, reason = _is_safe_url(url)\nif not is_safe:\n    raise ValueError(f\"URL is blocked for security reasons: {reason}\")\n\nfetch_timeout = 10\n\nclient = requests.Session()\nclient.max_redirects = 3\nresponse = client.get(url, timeout=fetch_timeout, allow_redirects=True)\n```\nWhen an attacker uses http://127.0.0.1:6666/, the existing detection logic can detect that this is an internal network address and block it.\n<img width=\"1286\" height=\"195\" alt=\"QQ20260416-204234-16-3\" src=\"https://github.com/user-attachments/assets/b921ff01-3b9f-49a5-a410-bd21fe42f9c9\" />\nHowever, when an attacker uses `http://127.0.0.1:6666\\@1.1.1.1`, the detection logic resolves the host to `1.1.1.1`, which is a public IP address, thus passing the verification. But in the actual request process, this URL is forwarded by requests.get to `http://127.0.0.1:6666/`, bypassing the detection and achieving an SSRF attack.\n\n<img width=\"2064\" height=\"154\" alt=\"QQ20260416-204319-16-4\" src=\"https://github.com/user-attachments/assets/5da18f35-f400-46e6-9bf3-1330ba424b02\" />\n\n### PoC\n```\nhttp://127.0.0.1:6666\\@1.1.1.1\n```\n\n### Impact\nSSRF","published":"2026-09-18T17:14:06Z","modified":"2026-09-18T17:30:08.470133113Z","cvss":{"score":7.5,"severity":"HIGH","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N"},"epss":null,"cisaKev":null,"exploitsKnown":null,"affectedPackages":[{"ecosystem":"PyPI","name":"lmdeploy","fixedVersion":"0.15.0"}],"fix":null,"references":[{"type":"WEB","url":"https://github.com/InternLM/lmdeploy/security/advisories/GHSA-39wr-7q6h-cf68"},{"type":"PACKAGE","url":"https://github.com/InternLM/lmdeploy"},{"type":"WEB","url":"https://github.com/InternLM/lmdeploy/releases/tag/v0.15.0"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-09-18T17:30:08.470133113Z"}}