peass-ng/PEASS-ng · error · ArgumentException

Path is a zero-length string or contains only white space.

Error message

Path is a zero-length string or contains only white space.

What it means

The sourcePath passed to File.Move / CopyMove is validated to not be a zero-length or all-whitespace string. An empty/whitespace source yields ArgumentException(Resources.Path_Is_Zero_Length_Or_Only_White_Space, "sourcePath").

Source

Thrown at winPEAS/winPEASexe/winPEAS/3rdParty/AlphaFS/Filesystem/File Class/File CopyMove/File.ValidateFileOrDirectoryMoveArguments.cs:66

         cma.IsCopy = IsCopyAction(cma);

         if (!cma.IsCopy)
            cma.DelayUntilReboot = VerifyDelayUntilReboot(sourcePath, cma.MoveOptions, cma.PathFormat);


         if (cma.PathFormat != PathFormat.LongFullPath)
         {
            if (null == sourcePath)
               throw new ArgumentNullException("sourcePath");
            
            // File Move action: destinationPath is allowed to be null when MoveOptions.DelayUntilReboot is specified.

            if (!cma.DelayUntilReboot && null == destinationPath)
               throw new ArgumentNullException("destinationPath");
            

            if (sourcePath.Trim().Length == 0)
               throw new ArgumentException(Resources.Path_Is_Zero_Length_Or_Only_White_Space, "sourcePath");

            if (null != destinationPath && destinationPath.Trim().Length == 0)
               throw new ArgumentException(Resources.Path_Is_Zero_Length_Or_Only_White_Space, "destinationPath");


            // MSDN: .NET3.5+: IOException: The sourceDirName and destDirName parameters refer to the same file or directory.
            // Do not use StringComparison.OrdinalIgnoreCase to allow renaming a folder with different casing.

            if (sourcePath.Equals(destinationPath, StringComparison.Ordinal))
               NativeError.ThrowException(Win32Errors.ERROR_SAME_DRIVE, destinationPath);


            if (!driveChecked)
            {
               // Check for local or network drives, such as: "C:" or "\\server\c$" (but not for "\\?\GLOBALROOT\").
               if (!sourcePath.StartsWith(Path.GlobalRootPrefix, StringComparison.OrdinalIgnoreCase))
                  Directory.ExistsDriveOrFolderOrFile(cma.Transaction, sourcePath, isFolder, (int) Win32Errors.NO_ERROR, true, false);

View on GitHub (pinned to 53fb989abc)

Solutions

Provide a real source path; check string.IsNullOrWhiteSpace(sourcePath) before calling.
Fail early with a domain-specific message when the configured source is blank.
Trim and validate user/config input at the boundary before constructing paths.

Example fix

// before
File.Move(srcPath, dstPath); // ArgumentException if srcPath is " "
// after
if (string.IsNullOrWhiteSpace(srcPath))
    throw new ArgumentException("Source path must not be empty.", nameof(srcPath));
File.Move(srcPath, dstPath);

Defensive patterns

Strategy: validation

Validate before calling

if (string.IsNullOrWhiteSpace(sourcePath))
    throw new ArgumentException("sourcePath must not be empty or whitespace.", nameof(sourcePath));

Type guard

static bool IsNonEmptyPath(string p) => !string.IsNullOrWhiteSpace(p);

Try / catch

try { File.Move(sourcePath, destinationPath); }
catch (ArgumentException ex) when (ex.ParamName == "sourcePath")
{
    // blank source: skip or surface a configuration error
    return;
}

Prevention

Use string.IsNullOrWhiteSpace checks on every path argument at API boundaries
Trim and verify values read from config, env vars, or string splits
Prefer explicit failure over silently passing empty strings downstream

When it happens

Trigger: Calling File.Move("", dst), File.Move(" ", dst), or CopyMove with a source that trims to empty (and PathFormat not LongFullPath).

Common situations: Empty environment variables or config keys feeding the path; string splitting producing empty segments; database/registry fields containing whitespace.

Related errors

AI-assisted analysis of peass-ng/PEASS-ng@53fb989abc (2026-09-02). Data as JSON: /api/errors/0e669566797ed6cb. Report an issue: GitHub.