Example - 1

In the following code examples a temporary file is created and written to. After using the temporary file, the file is closed and deleted from the file system.

perror("Could not open new temporary file\n");return (-1);
// // write data to tmp file// 
FILE *stream;if( (stream = tmpfile()) == NULL ) {}...// remove tmp filermtmp();

However, within this C/C++ code the method tmpfile() is used to create and open the temp file. The tmpfile() method works the same way as the fopen() method would with read/write permission, allowing attackers to read potentially sensitive information contained in the temp file or modify the contents of the file.

File temp = File.createTempFile("pattern", ".suffix");temp.deleteOnExit();BufferedWriter out = new BufferedWriter(new FileWriter(temp));out.write("aString");out.close();
try {}catch (IOException e) {}

Similarly, the createTempFile() method used in the Java code creates a temp file that may be readable and writable to all users.

Additionally both methods used above place the file into a default directory. On UNIX systems the default directory is usually "/tmp" or "/var/tmp" and on Windows systems the default directory is usually "C:\\Windows\\Temp", which may be easily accessible to attackers, possibly enabling them to read and modify the contents of the temp file.