"details": "### Summary\n\nThe patch for CVE-2026-32013 introduced symlink resolution and workspace boundary enforcement for `agents.files.get` and `agents.files.set`. However, two other handlers in the same file (`agents.create` and `agents.update`) still use raw `fs.appendFile` on the `IDENTITY.md` file **without any symlink containment check**. An attacker who can place a symlink in the agent workspace can hijack the `IDENTITY.md` path to append attacker-controlled content to arbitrary files on the system.\n\n### Details\n\nIn `src/gateway/server-methods/agents.ts`, the `agents.create` handler constructs the identity path and appends agent metadata without verifying symlinks:\n\n```typescript\n// agents.create — line 283-291\nconst identityPath = path.join(workspaceDir, DEFAULT_IDENTITY_FILENAME);\nconst lines = [\n \"\",\n `- Name: ${safeName}`,\n ...(emoji ? [`- Emoji: ${sanitizeIdentityLine(emoji)}`] : []),\n ...(avatar ? [`- Avatar: ${sanitizeIdentityLine(avatar)}`] : []),\n \"\",\n];\nawait fs.appendFile(identityPath, lines.join(\"\\n\"), \"utf-8\"); // ← NO SYMLINK CHECK\n```\n\nThe `agents.update` handler has the same issue at line 348-349:\n\n```typescript\n// agents.update — line 348-349\nconst identityPath = path.join(workspace, DEFAULT_IDENTITY_FILENAME);\nawait fs.appendFile(identityPath, `\\n- Avatar: ${sanitizeIdentityLine(avatar)}\\n`, \"utf-8\"); // ← NO SYMLINK CHECK\n```\n\n`fs.appendFile` follows symlinks by default. If the `IDENTITY.md` file in the workspace is a symlink pointing to a sensitive file (e.g., `/etc/crontab`, `~/.bashrc`, or `~/.ssh/authorized_keys`), calling `agents.create` will append the agent identity metadata to that file.\n\nThe `ensureAgentWorkspace` function (called at line 274 before the append) uses exclusive-create mode (`flag: 'wx'`) for `IDENTITY.md`. If a symlink already exists at that path, the `EEXIST` error is silently caught, and the subsequent `fs.appendFile` follows the symlink.\n\n**Attack flow:**\n```\n1. Attacker plants symlink: workspace/IDENTITY.md → /etc/crontab\n2. ensureAgentWorkspace skips creation (EEXIST from symlink)\n3. fs.appendFile follows symlink → writes to /etc/crontab\n4. Attacker-controlled content (name, emoji, avatar) injected into crontab → RCE\n```\n\n### PoC\n\n**Prerequisites:** Docker and Python 3 installed.\n\n**Step 1: Build and start the test environment.**\n```bash\ncd llm-enhance/cve-finding/RCE/CVE-2026-32013-identity-appendFile-variant-exp/\ndocker compose up -d --build\nsleep 3\n```\n\n**Step 2: Run the exploit.**\n```bash\npython3 poc_exploit.py\n```\n\nThis script:\n1. Plants a symlink `IDENTITY.md → /etc/target-file.txt` inside the agent workspace\n2. Calls the `agents.create` API endpoint via HTTP POST\n3. Verifies that the agent identity metadata was appended to `/etc/target-file.txt`\n\n**Step 3: Run the control experiment.**\n```bash\npython3 control-patched_realpath.py\n```\n\n**Step 4: Cleanup.**\n```bash\ndocker compose down\n```\n\n### Log of Evidence\n\n**Exploit output:**\n```\n=== CVE-2026-32013 Variant: Symlink Traversal via IDENTITY.md appendFile ===\n[*] Planting symlink: IDENTITY.md -> /etc/target-file.txt\n[*] Symlink: lrwxrwxrwx 1 root root 20 /workspaces/evil-agent/IDENTITY.md -> /etc/target-file.txt\n[*] Original /etc/target-file.txt: ORIGINAL_SENSITIVE_CONTENT\n\n[*] Calling agents.create with name='evil-agent'...\n[*] API response: {'ok': True, 'agentId': 'evil-agent', 'workspace': '/workspaces/evil-agent'}\n\n[*] /etc/target-file.txt after exploit:\n ORIGINAL_SENSITIVE_CONTENT\n\n- Name: evil-agent\n- Emoji: 💀\n- Avatar: evil.png\n\n[+] SUCCESS! Symlink traversal confirmed.\n[+] fs.appendFile followed IDENTITY.md symlink and wrote to /etc/target-file.txt\n[+] Attacker-controlled content injected into arbitrary file.\n```\n\n**Control output:**\n```\n=== CONTROL: Patched agents.create blocks symlink traversal ===\n[*] Planting symlink: IDENTITY.md -> /etc/target-file.txt\n[*] Original /etc/target-file.txt: ORIGINAL_SENSITIVE_CONTENT\n\n[*] Calling PATCHED agents.create with name='safe-agent'...\n[*] API response: {'ok': False, 'error': 'symlink_traversal_blocked', 'realPath': '/etc/target-file.txt'}\n\n[*] /etc/target-file.txt after patched call: ORIGINAL_SENSITIVE_CONTENT\n\n[+] CONTROL PASSED: Patched endpoint detected and blocked symlink traversal.\n[+] /etc/target-file.txt remains unchanged.\n```\n\n### Impact\n\nAn attacker who can plant a symlink in the agent workspace directory can use the `agents.create` or `agents.update` gateway API to **append attacker-controlled content to arbitrary files** on the system. If the target file is:\n\n- `/etc/crontab` or user crontab → **Remote Code Execution**\n- `~/.bashrc` or `~/.profile` → **Persistent code execution on login**\n- `~/.ssh/authorized_keys` → **Unauthorized SSH access**\n- Application configuration files → **Service disruption**\n\nThe attacker-controlled content includes the agent name (arbitrary string), emoji, and avatar fields, which are only lightly sanitized (whitespace normalization via `sanitizeIdentityLine`).\n\n### Affected products\n- **Ecosystem**: npm\n- **Package name**: openclaw\n- **Affected versions**: <= 2026.2.22\n- **Patched versions**: None\n\n### Occurrences\n\n| Permalink | Description |\n| :--- | :--- |\n| [https://github.com/openclaw/openclaw/blob/main/src/gateway/server-methods/agents.ts#L283-L291](https://github.com/openclaw/openclaw/blob/main/src/gateway/server-methods/agents.ts#L283-L291) | `agents.create` handler uses `fs.appendFile` on `IDENTITY.md` without symlink resolution or workspace boundary check. |\n| [https://github.com/openclaw/openclaw/blob/main/src/gateway/server-methods/agents.ts#L348-L349](https://github.com/openclaw/openclaw/blob/main/src/gateway/server-methods/agents.ts#L348-L349) | `agents.update` handler uses `fs.appendFile` on `IDENTITY.md` without symlink resolution or workspace boundary check. |\n| [https://github.com/openclaw/openclaw/blob/main/src/gateway/server-methods/agents.ts#L274](https://github.com/openclaw/openclaw/blob/main/src/gateway/server-methods/agents.ts#L274) | `ensureAgentWorkspace` is called before append, but its exclusive-create (`wx`) flag silently skips existing symlinks (EEXIST). |",
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