{"items":[{"id":"NVI-00017813","kind":"vulnerability","title":"yutu: Arbitrary File Write via MCP `caption-download` Tool","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-2c7f-fxww-6w6c","CVE-2026-50158"],"plain_summary":"GitHub lists this reviewed advisory for github.com/eat-pray-ai/yutu. Published version ranges and source prerequisites are shown below; this is not an inspection of a visitor’s application.","review_status":"source_listed","control_topics":[],"public_actions":[{"summary":"Identify the exact component and deployed version, examine the linked publisher’s conditions, and retain evidence of any mitigation.","source_ids":["sr-6c1271afb537485125e97d9991b45b93"],"action_type":"investigate","limitations":"Confirm current vendor support, compatibility and deployment evidence. This report has not tested a fix in your system.","current_supported_target":null}],"schema_version":"1.1.0","source_metrics":[{"kind":"CVSS","as_of":"2026-07-14T19:34:50.000Z","value":"7.7 high","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-6c1271afb537485125e97d9991b45b93"}],"why_it_matters":"Published affected context helps an owner decide what evidence to gather. This report has not examined your application.","related_sources":[{"id":"sr-6c1271afb537485125e97d9991b45b93","url":"https://github.com/advisories/GHSA-2c7f-fxww-6w6c","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-2c7f-fxww-6w6c","publisher":"GitHub Advisory Database","observed_at":"2026-11-04T23:34:12.429Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-6c1271afb537485125e97d9991b45b93"],"technology":"github.com/eat-pray-ai/yutu","known_exclusions":[],"conditions_summary":"## Arbitrary File Write via MCP `caption-download` Tool\n\n### Summary\n\nThe `caption-download` MCP tool in yutu passes the caller-supplied `file` parameter directly to `os.Create()` at `pkg/caption/caption.go:272` without any path validation, canonicalization, or confinement to the `pkg.Root` boundary (`YUTU_ROOT`). A local attacker — or any process able to reach the HTTP MCP server — can write arbitrary content to any path writable by the yutu process, entirely outside the intended working directory. This is a **High** severity vulnerability (CVSS 7.7) with high integrity and availability impact.\n\n### Details\n\nyutu uses `pkg.Root` (backed by Go 1.24's `os.OpenRoot`) to restrict all file I/O to the `YUTU_ROOT` directory. Every other caption file-write path honours this boundary:\n\n| Method | Sink | Confined? |\n|--------|------|-----------|\n| `Caption.Insert()` | `pkg.Root.Open(c.File)` (`caption.go:109`) | Yes |\n| `Caption.Update()` | `pkg.Root.Open(c.File)` (`caption.go:193`) | Yes |\n| `Caption.Download()` | `os.Create(c.File)` (`caption.go:272`) | **No** |\n\n`Caption.Download()` is the sole outlier. The attacker-controlled `file` field flows without restriction from the MCP tool inpu","public_affected_ranges":["< 0.10.9-dev1"]}],"null_published_at":"2026-11-05T19:10:21.471Z","source_updated_at":"2026-07-14T19:34:50.000Z","source_disclosed_at":"2026-07-14T19:34:47.000Z","is_synthetic_fixture":false,"null_last_reviewed_at":null,"public_change_summary":"First indexed by Null; source disclosure date is shown separately.","null_first_observed_at":"2026-11-04T23:34:12.429Z"}],"next_cursor":null,"snapshot_revision":"40769"}