fix: harden host exec env validation (#4896) (thanks @HassanFleyah)

CHANGELOG.md

@@ -29,6 +29,7 @@ Docs: https://docs.openclaw.ai
 - Browser: secure Chrome extension relay CDP sessions.
 - Docker: use container port for gateway command instead of host port. (#5110) Thanks @mise42.
 - fix(lobster): block arbitrary exec via lobsterPath/cwd injection (GHSA-4mhr-g7xj-cg8j). (#5335) Thanks @vignesh07.
+- Security: block LD_/DYLD_ env overrides for host exec. (#4896) Thanks @HassanFleyah.
 - Security: harden web tool content wrapping + file parsing safeguards. (#4058) Thanks @VACInc.
 
 ## 2026.1.30

docs/tools/exec.md

@@ -36,6 +36,8 @@ Notes:
 - If multiple nodes are available, set `exec.node` or `tools.exec.node` to select one.
 - On non-Windows hosts, exec uses `SHELL` when set; if `SHELL` is `fish`, it prefers `bash` (or `sh`)
   from `PATH` to avoid fish-incompatible scripts, then falls back to `SHELL` if neither exists.
+- Host execution (`gateway`/`node`) rejects `env.PATH` and loader overrides (`LD_*`/`DYLD_*`) to
+  prevent binary hijacking or injected code.
 - Important: sandboxing is **off by default**. If sandboxing is off, `host=sandbox` runs directly on
   the gateway host (no container) and **does not require approvals**. To require approvals, run with
   `host=gateway` and configure exec approvals (or enable sandboxing).
@@ -65,16 +67,16 @@ Example:
 
 ### PATH handling
 
-- `host=gateway`: merges your login-shell `PATH` into the exec environment (unless the exec call
-  already sets `env.PATH`). The daemon itself still runs with a minimal `PATH`:
+- `host=gateway`: merges your login-shell `PATH` into the exec environment. `env.PATH` overrides are
+  rejected for host execution. The daemon itself still runs with a minimal `PATH`:
   - macOS: `/opt/homebrew/bin`, `/usr/local/bin`, `/usr/bin`, `/bin`
   - Linux: `/usr/local/bin`, `/usr/bin`, `/bin`
 - `host=sandbox`: runs `sh -lc` (login shell) inside the container, so `/etc/profile` may reset `PATH`.
   OpenClaw prepends `env.PATH` after profile sourcing via an internal env var (no shell interpolation);
   `tools.exec.pathPrepend` applies here too.
-- `host=node`: only env overrides you pass are sent to the node. `tools.exec.pathPrepend` only applies
-  if the exec call already sets `env.PATH`. Headless node hosts accept `PATH` only when it prepends
-  the node host PATH (no replacement). macOS nodes drop `PATH` overrides entirely.
+- `host=node`: only non-blocked env overrides you pass are sent to the node. `env.PATH` overrides are
+  rejected for host execution. Headless node hosts accept `PATH` only when it prepends the node host
+  PATH (no replacement). macOS nodes drop `PATH` overrides entirely.
 
 Per-agent node binding (use the agent list index in config):
 

src/agents/bash-tools.exec.path.test.ts

@@ -109,3 +109,17 @@ describe("exec PATH login shell merge", () => {
     expect(shellPathMock).not.toHaveBeenCalled();
   });
 });
+
+describe("exec host env validation", () => {
+  it("blocks LD_/DYLD_ env vars on host execution", async () => {
+    const { createExecTool } = await import("./bash-tools.exec.js");
+    const tool = createExecTool({ host: "gateway", security: "full", ask: "off" });
+
+    await expect(
+      tool.execute("call1", {
+        command: "echo ok",
+        env: { LD_DEBUG: "1" },
+      }),
+    ).rejects.toThrow(/Security Violation: Environment variable 'LD_DEBUG' is forbidden/);
+  });
+});

src/agents/bash-tools.exec.ts

@@ -76,6 +76,7 @@ const DANGEROUS_HOST_ENV_VARS = new Set([
   "IFS",
   "SSLKEYLOGFILE",
 ]);
+const DANGEROUS_HOST_ENV_PREFIXES = ["DYLD_", "LD_"];
 
 // Centralized sanitization helper.
 // Throws an error if dangerous variables or PATH modifications are detected on the host.
@@ -84,6 +85,11 @@ function validateHostEnv(env: Record<string, string>): void {
     const upperKey = key.toUpperCase();
 
     // 1. Block known dangerous variables (Fail Closed)
+    if (DANGEROUS_HOST_ENV_PREFIXES.some((prefix) => upperKey.startsWith(prefix))) {
+      throw new Error(
+        `Security Violation: Environment variable '${key}' is forbidden during host execution.`,
+      );
+    }
     if (DANGEROUS_HOST_ENV_VARS.has(upperKey)) {
       throw new Error(
         `Security Violation: Environment variable '${key}' is forbidden during host execution.`,