{"items":[{"id":"NVI-00018262","kind":"vulnerability","title":"OpenClaude MCP OAuth Callback: State Check Bypass via error Param Leads to DoS","revision":1,"unknowns":["Customer inventory, deployment, reachability and exploitation have not been inspected."],"lifecycle":"active","identifiers":["GHSA-c73c-x77g-854r","CVE-2026-42073"],"plain_summary":"GitHub lists this reviewed advisory for @gitlawb/openclaude. 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-01f8062174ac60e001189049f7bd32ba"],"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":"2026-06-09T10:59:33.000Z","value":"6.5 medium","meaning":"GitHub source severity; exploitability and local consequence require separate evidence.","source_id":"sr-01f8062174ac60e001189049f7bd32ba"}],"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-01f8062174ac60e001189049f7bd32ba","url":"https://github.com/advisories/GHSA-c73c-x77g-854r","basis":"vendor_advisory","notes":"GitHub Advisory Database; CC-BY-4.0. Each advisory links its original attribution. Null normalizes fields.","title":"GHSA-c73c-x77g-854r","publisher":"GitHub Advisory Database","observed_at":"2026-11-06T20:56:39.448Z"}],"affected_context":[{"certainty":"source_listed","source_ids":["sr-01f8062174ac60e001189049f7bd32ba"],"technology":"@gitlawb/openclaude","known_exclusions":[],"conditions_summary":"# OAuth State Validation Bypass via `error` Parameter Causes Local Server DoS in MCP Auth Callback\n---\n\n## Description\n\nThe OpenClaude MCP authentication flow starts a temporary local HTTP server to handle OAuth callbacks. To prevent CSRF attacks, the server validates a `state` parameter against an internally stored value. However, due to a logic flaw in the order of conditionals, an attacker can completely bypass this check and force the server to shut down — without knowing the `state` value at all.\n\nThe vulnerable code looks like this:\n\n```typescript\nif (!error && state !== oauthState) {\n    rejectOnce(new Error('OAuth state mismatch - possible CSRF attack'))\n    return\n}\n\nif (error) {\n    cleanup()\n    rejectOnce(new Error(errorMessage))\n    return\n}\n```\n\nWhen a request arrives with an `error` query parameter (e.g., `?error=anything`), the first condition becomes `false` because `!error` evaluates to `false`. This means the CSRF check is **never reached**. Execution falls through to the second block, where `cleanup()` is called — shutting down the local server and terminating the user's active authentication session.\n\nThe attacker does not need to know the `state` value. Any re","public_affected_ranges":["< 0.5.1"]}],"null_published_at":"2026-11-07T07:07:39.796Z","source_updated_at":"2026-06-09T10:59:33.000Z","source_disclosed_at":"2026-05-12T15:34:30.000Z","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":"2026-11-06T20:56:39.448Z"}],"next_cursor":null,"snapshot_revision":"42594"}