fix(security): deny generated-image access when ownership verification fails (#6268)

* fix(security): deny generated-image access when ownership verification fails

The except Exception block in serve_generated_image catches all
exceptions during ownership verification and falls through to serve
the file anyway. If the database is down or corrupted, the ownership
check is bypassed entirely — any authenticated user can download any
generated image by guessing the content-hash filename.

Raise HTTP 503 (Service Unavailable) instead of falling through,
so the endpoint fails closed when verification is impossible. This
matches the defense-in-depth principle: deny access on verification
errors rather than granting it.

* fix(security): enforce fail-closed ownership and secure caching for generated images

- Fail closed on missing gallery records, null/empty owners, and DB errors
- Support both cookie session and bearer API token owners via effective_user
- Add in-memory registry for freshly generated images to preserve access
- Eliminate file existence oracle by verifying ownership before disk probing
- Update Cache-Control to private, no-cache, must-revalidate
- Pass owner attribution through tool execution and image MCP server
- Add comprehensive hermetic regression tests for ownership gates and caching

* fix(security): sanitize tool owner arguments and drop unneeded MCP env fallback

- Remove redundant and unsafe ODYSSEUS_MCP_IMAGE_OWNER fallback in image_gen_server.py to fix 4 tests in test_env_reference.py.
- Sanitize caller-supplied tool arguments across all MCP and email tool dispatch paths in src/tool_execution.py: strip untrusted _odysseus_* keys from arguments.
- Only inject _odysseus_owner when verified trusted server context is present, preventing untrusted/anonymous users from spoofing ownership claims.
- Sanitize empty/whitespace owner strings in image_gen_server.py to None.
- Add comprehensive regression tests in test_generated_image_ownership.py for argument sanitization, owner injection, fallback propagation, and server sanitization.

---------

Co-authored-by: isharak7m <192635824+isharak7m@users.noreply.github.com>
Co-authored-by: PR #6166 Reviewer <reviewer@odysseus-review.local>
This commit is contained in:
Isharak
2026-10-14 12:18:50 +01:00
committed by GitHub
co-authored by isharak7m PR #6166 Reviewer
parent 501059805f
commit 6fceb6ccd3
7 changed files with 643 additions and 39 deletions
+28 -12
View File
@@ -1317,7 +1317,8 @@ def _parse_qualified_mcp_args(tool: str, content: str) -> tuple[Dict, Optional[s
if tool.startswith("mcp__email__"):
return {}, "Email MCP tool arguments must be a JSON object."
return {}, None
return parsed, None
sanitized = {k: v for k, v in parsed.items() if not k.startswith("_odysseus_")}
return sanitized, None
def _parse_generate_image(content: str) -> Dict:
@@ -1402,9 +1403,12 @@ def _build_mcp_args(tool: str, content: str) -> Dict:
except (json.JSONDecodeError, TypeError):
decoded = None
if isinstance(decoded, dict) and any(k in decoded for k in primaries):
return decoded
return {k: v for k, v in decoded.items() if not k.startswith("_odysseus_")}
parser = _MCP_ARG_PARSERS.get(tool)
return parser(content) if parser else {}
res = parser(content) if parser else {}
if isinstance(res, dict):
return {k: v for k, v in res.items() if not k.startswith("_odysseus_")}
return res
def _normalize_mcp_text_error(result: Dict) -> Dict:
@@ -1421,20 +1425,25 @@ async def _call_mcp_tool(
tool: str,
content: str,
progress_cb: Optional[Callable[[Dict], Awaitable[None]]] = None,
owner: Optional[str] = None,
) -> Dict:
"""Route a legacy tool call through the MCP manager, with direct fallbacks."""
bound = active_backend_operation()
if bound is not None and isinstance(bound.resource, NativeBackendResource):
return await _direct_fallback(tool, content, progress_cb=progress_cb) or {"error": f"Native tool '{tool}' unavailable", "exit_code": 1}
return await _direct_fallback(tool, content, progress_cb=progress_cb, owner=owner) or {"error": f"Native tool '{tool}' unavailable", "exit_code": 1}
mcp = get_mcp_manager()
if not mcp:
if bound is not None:
raise ResourceIdentityError("Pinned MCP backend is unavailable")
return await _direct_fallback(tool, content, progress_cb=progress_cb) or {"error": f"MCP manager not available for tool '{tool}'", "exit_code": 1}
return await _direct_fallback(tool, content, progress_cb=progress_cb, owner=owner) or {"error": f"MCP manager not available for tool '{tool}'", "exit_code": 1}
server_id, tool_name = _MCP_TOOL_MAP[tool]
qualified = f"mcp__{server_id}__{tool_name}"
args = _build_mcp_args(tool, content)
if tool == "generate_image":
args.pop("_odysseus_owner", None)
if owner:
args["_odysseus_owner"] = owner
result = await mcp.call_tool(qualified, args)
# Stdio MCP servers can only return TextContent, so an explicit
@@ -1444,7 +1453,7 @@ async def _call_mcp_tool(
# If MCP server not connected, try direct fallback
if bound is None and isinstance(result, dict) and result.get("exit_code") == 1 and "not connected" in result.get("error", ""):
fallback = await _direct_fallback(tool, content, progress_cb=progress_cb)
fallback = await _direct_fallback(tool, content, progress_cb=progress_cb, owner=owner)
if fallback:
return fallback
@@ -2193,7 +2202,7 @@ async def _execute_tool_block_impl(
elif tool in _MCP_TOOL_MAP:
first_line = content.split(chr(10))[0][:80]
desc = f"{tool}: {first_line}"
result = await dispatched(_call_mcp_tool(tool, content, progress_cb=progress_cb))
result = await dispatched(_call_mcp_tool(tool, content, progress_cb=progress_cb, owner=owner))
elif tool in ("grep", "glob", "ls", "get_workspace", "host_shell"):
# Code-navigation tools — no MCP server; run the direct implementation.
first_line = content.split(chr(10))[0][:80]
@@ -2379,7 +2388,7 @@ async def _execute_tool_block_impl(
)
else:
if isinstance(parsed, dict):
args = parsed
args = {k: v for k, v in parsed.items() if not k.startswith("_odysseus_")}
else:
_args_error = (
f"'{tool}' arguments must be a JSON object, "
@@ -2388,11 +2397,12 @@ async def _execute_tool_block_impl(
if _args_error is not None:
result = {"error": _args_error, "exit_code": 1}
else:
args = dict(args)
args.pop(_EMAIL_MCP_OWNER_ARG, None)
args.pop(_EMAIL_MCP_SESSION_ARG, None)
if owner:
args = dict(args)
args[_EMAIL_MCP_OWNER_ARG] = owner
if session_id:
args = dict(args)
args[_EMAIL_MCP_SESSION_ARG] = session_id
result = await dispatched(mcp.call_tool(qualified, args))
else:
@@ -2406,14 +2416,20 @@ async def _execute_tool_block_impl(
if parse_error:
result = {"error": parse_error, "exit_code": 1}
else:
args = dict(args)
args.pop("_odysseus_owner", None)
args.pop("_odysseus_session_id", None)
if tool.startswith("mcp__email__"):
if owner:
args = dict(args)
args[_EMAIL_MCP_OWNER_ARG] = owner
if session_id:
args = dict(args)
args[_EMAIL_MCP_SESSION_ARG] = session_id
elif tool == "mcp__image_gen__generate_image" or tool.startswith("mcp__image_gen__"):
if owner:
args["_odysseus_owner"] = owner
result = _normalize_mcp_text_error(await dispatched(mcp.call_tool(tool, args)))
if tool == "mcp__image_gen__generate_image" or tool.startswith("mcp__image_gen__"):
_promote_image_fields(result)
else:
desc = f"mcp: {tool}"
result = {"error": "MCP manager not available", "exit_code": 1}