FILEREADDATA

FILEREADDATA, more commonly referred to in Windows documentation as FILE_READ_DATA, is a file system access right in the Windows NT family that authorizes reading the data stored in a file object. It is part of the low-level access mask used by the security subsystem to control what operations a principal is permitted to perform on a file. For directories, the analogous read-right is FILE_LIST_DIRECTORY, not FILE_READ_DATA.

In the Windows security model, access rights are combined into an access mask. FILE_READ_DATA has the value 0x00000001 (the exact bit may be represented differently in various headers, but it corresponds to the fundamental read-data permission). This right can be requested directly in low-level APIs such as ZwOpenFile, or it can be encompassed by GENERIC_READ in higher-level APIs, which maps to a set of specific rights including FILE_READ_DATA.

Usage and implications: Granting FILE_READ_DATA allows a process to read the contents of a file. It is typically applied through Access Control Lists applied to the file’s security descriptor, and it interacts with other rights such as FILE_READ_ATTRIBUTES and FILE_WRITE_DATA. While many applications request GENERIC_READ to obtain broad read access, the explicit FILE_READ_DATA bit represents the actual permission to read file contents at the data stream level.

Notes: The canonical identifier in Windows headers is FILE_READ_DATA. FILEREADDATA is a variant sometimes seen in non-canonical references or as a lowercase/uppercase spelling, but it refers to the same underlying right. This right is part of the broader set of file-related access rights used in ACLs and security auditing.