diff --git a/internal/handler/webshell.go b/internal/handler/webshell.go
index 5b34c368..d6d828df 100644
--- a/internal/handler/webshell.go
+++ b/internal/handler/webshell.go
@@ -721,15 +721,22 @@ func (h *WebShellHandler) Exec(c *gin.Context) {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "url and command are required"})
 		return
 	}
-	conn, allowed := h.authorizedWebshellConnection(c, req.ConnectionID, req.URL)
-	if !allowed {
+	// Pre-save connectivity tests send form credentials without connection_id.
+	// Saved connections must go through resource ACL; DB credentials are authoritative.
+	if cid := strings.TrimSpace(req.ConnectionID); cid != "" {
+		conn, allowed := h.authorizedWebshellConnection(c, cid, req.URL)
+		if !allowed {
+			c.JSON(http.StatusForbidden, gin.H{"error": "无权访问该资源"})
+			return
+		}
+		// Never let a caller pair an authorized ID with attacker-controlled
+		// transport credentials or a URL.
+		req.URL, req.Password, req.Type = conn.URL, conn.Password, conn.Type
+		req.Method, req.CmdParam, req.Encoding = conn.Method, conn.CmdParam, conn.Encoding
+	} else if !security.SessionHasPermission(c, "webshell:write") {
 		c.JSON(http.StatusForbidden, gin.H{"error": "无权访问该资源"})
 		return
 	}
-	// The database record is authoritative. Never let a caller pair an
-	// authorized ID with attacker-controlled transport credentials or a URL.
-	req.URL, req.Password, req.Type = conn.URL, conn.Password, conn.Type
-	req.Method, req.CmdParam, req.Encoding = conn.Method, conn.CmdParam, conn.Encoding
 
 	parsed, err := url.Parse(req.URL)
 	if err != nil || (parsed.Scheme != "http" && parsed.Scheme != "https") {
@@ -823,13 +830,18 @@ func (h *WebShellHandler) FileOp(c *gin.Context) {
 		c.JSON(http.StatusBadRequest, gin.H{"error": "url and action are required"})
 		return
 	}
-	conn, allowed := h.authorizedWebshellConnection(c, req.ConnectionID, req.URL)
-	if !allowed {
+	if cid := strings.TrimSpace(req.ConnectionID); cid != "" {
+		conn, allowed := h.authorizedWebshellConnection(c, cid, req.URL)
+		if !allowed {
+			c.JSON(http.StatusForbidden, gin.H{"error": "无权访问该资源"})
+			return
+		}
+		req.URL, req.Password, req.Type = conn.URL, conn.Password, conn.Type
+		req.Method, req.CmdParam, req.Encoding, req.OS = conn.Method, conn.CmdParam, conn.Encoding, conn.OS
+	} else if !security.SessionHasPermission(c, "webshell:write") {
 		c.JSON(http.StatusForbidden, gin.H{"error": "无权访问该资源"})
 		return
 	}
-	req.URL, req.Password, req.Type = conn.URL, conn.Password, conn.Type
-	req.Method, req.CmdParam, req.Encoding, req.OS = conn.Method, conn.CmdParam, conn.Encoding, conn.OS
 
 	parsed, err := url.Parse(req.URL)
 	if err != nil || (parsed.Scheme != "http" && parsed.Scheme != "https") {
diff --git a/internal/handler/webshell_rbac_test.go b/internal/handler/webshell_rbac_test.go
index cea5676b..33b86e1e 100644
--- a/internal/handler/webshell_rbac_test.go
+++ b/internal/handler/webshell_rbac_test.go
@@ -40,15 +40,47 @@ func TestWebshellExecRequiresConnectionAccessWhenConnectionIDProvided(t *testing
 	}
 }
 
-func TestWebshellExecRejectsAdHocURLWithoutConnectionID(t *testing.T) {
+func TestWebshellExecAllowsAdHocURLWithoutConnectionID(t *testing.T) {
 	gin.SetMode(gin.TestMode)
 	_, user, _, _ := setupWebshellRBACTest(t)
 	handler := NewWebShellHandler(zap.NewNop(), nil)
+	// Ad-hoc probe (connectivity test before save) must not be rejected as "无权访问".
+	// The target URL will fail to connect; we only assert auth allows the request through.
 	w := performWebshellJSON(user, http.MethodPost, "/api/webshell/exec", map[string]interface{}{
-		"url": "http://127.0.0.1/admin", "command": "id",
+		"url": "http://127.0.0.1:1/admin", "command": "id",
 	}, handler.Exec)
+	if w.Code == http.StatusForbidden {
+		t.Fatalf("ad-hoc URL status = %d, want non-403: %s", w.Code, w.Body.String())
+	}
+	var resp ExecResponse
+	if err := json.Unmarshal(w.Body.Bytes(), &resp); err != nil {
+		t.Fatalf("decode response: %v body=%s", err, w.Body.String())
+	}
+	if resp.OK {
+		t.Fatalf("expected connection failure for closed port, got ok=true")
+	}
+}
+
+func TestWebshellExecRejectsAdHocWithoutWritePermission(t *testing.T) {
+	gin.SetMode(gin.TestMode)
+	user := &database.RBACUser{ID: "u_ro", Username: "readonly"}
+	handler := NewWebShellHandler(zap.NewNop(), nil)
+	payload, _ := json.Marshal(map[string]interface{}{
+		"url": "http://127.0.0.1/admin", "command": "id",
+	})
+	w := httptest.NewRecorder()
+	c, _ := gin.CreateTestContext(w)
+	c.Request = httptest.NewRequest(http.MethodPost, "/api/webshell/exec", bytes.NewReader(payload))
+	c.Request.Header.Set("Content-Type", "application/json")
+	c.Set(security.ContextSessionKey, security.Session{
+		UserID:      user.ID,
+		Username:    user.Username,
+		Permissions: map[string]bool{"webshell:read": true},
+		Scope:       database.RBACScopeAssigned,
+	})
+	handler.Exec(c)
 	if w.Code != http.StatusForbidden {
-		t.Fatalf("ad-hoc URL status = %d, want %d: %s", w.Code, http.StatusForbidden, w.Body.String())
+		t.Fatalf("status = %d, want %d: %s", w.Code, http.StatusForbidden, w.Body.String())
 	}
 }