{"id":"CVE-2026-35570","aliases":["GHSA-m6rx-7pvw-2f73"],"url":"https://o3.security/vulnerability/CVE-2026-35570","summary":"OpenClaude has Sandbox Bypass via Early-Exit Logic Flaw that Allows Path Traversal","details":"A logic flaw exists in `bashToolHasPermission()` inside `src/tools/BashTool/bashPermissions.ts`. When the sandbox auto-allow feature is active and no explicit deny rule is configured, the function returns an `allow` result immediately — before the path constraint filter (`checkPathConstraints`) is ever evaluated. This allows commands containing path traversal sequences (e.g., `../../../../../etc/passwd`) to bypass directory restrictions entirely.\n\n## Affected Component\n\n- **File:** `src/tools/BashTool/bashPermissions.ts`\n- **Function:** `bashToolHasPermission`\n- **Location:** ~line 1445 (sandbox auto-allow block)\n\n## Vulnerable Code Flow\n\n```\nbashToolHasPermission()\n    │\n    ├─ [~1445] Sandbox auto-allow block\n    │       └─ No deny rule found → return ALLOW  ⚠️ Early exit\n    │\n    └─ [~1644] checkPathConstraints()             ❌ Never reached\n```\n\nThe sandbox block was designed to skip interactive permission prompts in sandboxed environments. However, it unintentionally also skips the path traversal filter, which is a separate and critical security control.\n\n## Impact\n\nAny process or user operating in a sandboxed session with no explicit deny rules can:\n\n- Read arbitrary files outside the sandbox boundary (e.g., `/etc/passwd`, `/etc/shadow`, `.env` files, SSH private keys)\n- Write to arbitrary paths (subject to OS-level permissions)\n- Fully defeat the filesystem isolation that the sandbox is intended to enforce\n\n## Steps to Reproduce\n\n1. Enable sandbox mode: `SandboxManager.isSandboxingEnabled() = true`\n2. Enable auto-allow: `SandboxManager.isAutoAllowBashIfSandboxedEnabled() = true`\n3. Ensure no explicit deny rules are configured for the session\n4. Submit a bash command with a path traversal payload:\n   ```\n   cat ../../../../../etc/passwd\n   ```\n5. Observe that the command receives `behavior: allow` without triggering `checkPathConstraints`\n\n## Recommended Fix\n\nThe sandbox auto-allow block should **never short-circuit the full permission pipeline**. It may suppress interactive prompts, but path constraint validation must always execute.\n\n### Option 1 — Preferred: Continue pipeline on `allow`\n\nOnly return early for `deny` or `ask` behaviors. Let `allow` fall through to `checkPathConstraints`:\n\n```typescript\nif (\n  SandboxManager.isSandboxingEnabled() &&\n  SandboxManager.isAutoAllowBashIfSandboxedEnabled() &&\n  shouldUseSandbox(input)\n) {\n  const sandboxAutoAllowResult = checkSandboxAutoAllow(\n    input,\n    appState.toolPermissionContext,\n  );\n  if (sandboxAutoAllowResult.behavior !== 'allow') {\n    // Only block or prompt — never skip path checks on allow\n    return sandboxAutoAllowResult;\n  }\n  // If 'allow', continue to checkPathConstraints below\n}\n```\n\n### Option 2 — Defense in depth: Run path check before returning\n\nRun `checkPathConstraints` explicitly inside the sandbox block before returning:\n\n```typescript\nif (sandboxAutoAllowResult.behavior !== 'passthrough') {\n  const pathCheck = checkPathConstraints(input, appState.toolPermissionContext);\n  if (pathCheck.behavior !== 'allow') {\n    return pathCheck; // Block traversal attempts even in sandbox\n  }\n  return sandboxAutoAllowResult;\n}\n```\n\n### Option 3 — Minimal change: Move sandbox block after path check\n\nReorder the function so `checkPathConstraints` always runs first, and the sandbox block only handles the prompt-suppression logic afterward.\n\n---\n\nCredit: Elvin Latifli (@Rickidevs )","published":"2026-04-20T23:24:08.324Z","modified":"2026-08-12T03:51:44.737937419Z","cvss":{"score":8.4,"severity":"HIGH","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:C/C:H/I:H/A:N"},"epss":{"score":0.00232,"percentile":0.14184,"asOf":"2026-08-14"},"cisaKev":null,"exploitsKnown":0,"affectedPackages":[{"ecosystem":"npm","name":"@gitlawb/openclaude","fixedVersion":"0.5.1"}],"fix":{"url":"https://github.com/Gitlawb/openclaude/commit/7002cb302b78ea2a19da3f26226de24e2903fa1d","label":"Gitlawb/openclaude@7002cb3"},"references":[{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/35xxx/CVE-2026-35570.json"},{"type":"ADVISORY","url":"https://github.com/Gitlawb/openclaude/security/advisories/GHSA-m6rx-7pvw-2f73"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-35570"},{"type":"FIX","url":"https://github.com/Gitlawb/openclaude/commit/7002cb302b78ea2a19da3f26226de24e2903fa1d"},{"type":"PACKAGE","url":"https://github.com/Gitlawb/openclaude"}],"provenance":{"sources":["OSV.dev","FIRST.org (EPSS)"],"lastVerified":"2026-08-12T03:51:44.737937419Z"}}