peass-ng/PEASS-ng · error · ArgumentOutOfRangeException

A maximum of 32 parameters can be supplied to RunEx.

Error message

A maximum of 32 parameters can be supplied to RunEx.

What it means

RunEx documents this NotV1SupportedException condition: Task Scheduler 1.0 (Windows XP/2000) does not support RunEx's extended run options, so invoking RunEx on a v1 system throws this exception. It is a platform-capability error, not a data validation failure.

Source

Thrown at winPEAS/winPEASexe/winPEAS/TaskScheduler/Task.cs:1479

        /// <para>If RunEx is invoked from a disabled task, it will return <c>null</c> and the task will not be run.</para>
        /// </remarks>
        /// <exception cref="NotV1SupportedException">Not supported under Task Scheduler 1.0.</exception>
        /// <example>
        /// <code lang="cs">
        ///<![CDATA[
        /// // Run the current task with a parameter as a different user and ignoring any of the conditions.
        /// var runningTask = myTaskInstance.RunEx(TaskRunFlags.IgnoreConstraints, 0, "DOMAIN\\User", "info");
        /// Console.Write(string.Format("Running task's current action is {0}.", runningTask.CurrentAction));
        ///]]>
        /// </code>
        /// </example>
        public RunningTask RunEx(TaskRunFlags flags, int sessionID, string user, params string[] parameters)
        {
            if (v2Task == null) throw new NotV1SupportedException();
            if (parameters == null || parameters.Any(s => s == null))
                throw new ArgumentNullException(nameof(parameters), "The array and none of the values passed as parameters may be `null`.");
            if (parameters.Length > 32)
                throw new ArgumentOutOfRangeException(nameof(parameters), "A maximum of 32 parameters can be supplied to RunEx.");
            if (TaskService.HighestSupportedVersion < TaskServiceVersion.V1_5 && parameters.Any(p => (p?.Length ?? 0) >= 260))
                throw new ArgumentOutOfRangeException(nameof(parameters), "On systems prior to Windows 10, no individual parameter may be more than 260 characters.");
            var irt = v2Task.RunEx(parameters.Length == 0 ? null : parameters, (int)flags, sessionID, user);
            return irt != null ? new RunningTask(TaskService, v2Task, irt) : null;
        }

        /// <summary>
        /// Applies access control list (ACL) entries described by a <see cref="TaskSecurity"/> object to the file described by the current
        /// <see cref="Task"/> object.
        /// </summary>
        /// <param name="taskSecurity">
        /// A <see cref="TaskSecurity"/> object that describes an access control list (ACL) entry to apply to the current task.
        /// </param>
        /// <example>
        /// <para>Give read access to all authenticated users for a task.</para>
        /// <code lang="cs">
        ///<![CDATA[
        /// // Assume variable 'task' is a valid Task instance

View on GitHub (pinned to 53fb989abc)

Solutions

1. Reduce the argument count to 32 or fewer
2. Pack multiple values into a single delimited parameter or a config file and pass its path
3. Use ArgumentString-style approaches (encode all args into one quoted string if the target executable parses it)
4. Split the work across multiple task runs

Example fix

// before
task.RunEx(flags, 0, null, allFiles); // allFiles.Length may exceed 32
// after
var args = allFiles.Take(32).ToArray();
task.RunEx(flags, 0, null, args);

if (parameters != null && parameters.Length > 32)
    throw new ArgumentException("RunEx accepts at most 32 parameters");

try { task.RunEx(flags, sid, user, parameters); }
catch (ArgumentOutOfRangeException) { /* pack args into a file or split runs */ }

When it happens

Trigger: Calling task.RunEx(flags, sessionID, user, params) with parameters.Length > 32.

Common situations: Forwarding an unbounded argument list (e.g. all files in a folder, a large set of flags) directly to the task; scripts that accumulate arguments programmatically.

Related errors

• Data Overflow
• A maximum of 32 actions is allowed within a single task.
• Attachments array cannot contain more than 8 items.
• Each value of the array must contain a valid file reference.
• Under Windows 8 and later, EmailAction objects are converted

AI-assisted analysis of peass-ng/PEASS-ng@53fb989abc (2026-09-02). Data as JSON: /api/errors/c0566bcba4b73249. Report an issue: GitHub.