In Unix, "others" class refers to all users except the owner of the file and the members of the group assigned to this file.
In Windows, "Everyone" group is similar and includes all members of the Authenticated Users group as well as the built-in Guest account, and
several other built-in security accounts.
Granting permissions to these groups can lead to unintended access to files.
Ask Yourself Whether
- The application is designed to be run on a multi-user environment.
- Corresponding files and directories may contain confidential information.
There is a risk if you answered yes to any of those questions.
Recommended Secure Coding Practices
The most restrictive possible permissions should be assigned to files and directories.
Sensitive Code Example
.Net Framework:
Dim unsafeAccessRule = new FileSystemAccessRule("Everyone", FileSystemRights.FullControl, AccessControlType.Allow)
Dim fileSecurity = File.GetAccessControl("path")
fileSecurity.AddAccessRule(unsafeAccessRule) ' Sensitive
fileSecurity.SetAccessRule(unsafeAccessRule) ' Sensitive
File.SetAccessControl("fileName", fileSecurity)
.Net / .Net Core
Dim fileInfo = new FileInfo("path")
Dim fileSecurity = fileInfo.GetAccessControl()
fileSecurity.AddAccessRule(new FileSystemAccessRule("Everyone", FileSystemRights.Write, AccessControlType.Allow)) ' Sensitive
fileInfo.SetAccessControl(fileSecurity)
.Net / .Net Core using Mono.Posix.NETStandard
Dim fileSystemEntry = UnixFileSystemInfo.GetFileSystemEntry("path")
fileSystemEntry.FileAccessPermissions = FileAccessPermissions.OtherReadWriteExecute ' Sensitive
Compliant Solution
.Net Framework
Dim safeAccessRule = new FileSystemAccessRule("Everyone", FileSystemRights.FullControl, AccessControlType.Deny)
Dim fileSecurity = File.GetAccessControl("path")
fileSecurity.AddAccessRule(safeAccessRule)
File.SetAccessControl("path", fileSecurity)
.Net / .Net Core
Dim safeAccessRule = new FileSystemAccessRule("Everyone", FileSystemRights.FullControl, AccessControlType.Deny)
Dim fileInfo = new FileInfo("path")
Dim fileSecurity = fileInfo.GetAccessControl()
fileSecurity.SetAccessRule(safeAccessRule)
fileInfo.SetAccessControl(fileSecurity)
.Net / .Net Core using Mono.Posix.NETStandard
Dim fs = UnixFileSystemInfo.GetFileSystemEntry("path")
fs.FileAccessPermissions = FileAccessPermissions.UserExecute
See
