CWE-379: Creation of Temporary File in Directory with Incorrect Permissions
Creation of Temporary File in Directory with Incorrect Permissions
Weakness ID: 379 (Weakness Base)
Status: Incomplete
Description
Description Summary
The software creates a temporary file in a directory whose
permissions allow unintended actors to determine the file's existence or
otherwise access that file.
Extended Description
On some operating systems, the fact that the temporary file exists may be
apparent to any user with sufficient privileges to access that directory.
Since the file is visible, the application that is using the temporary file
could be known. If one has access to list the processes on the system, the
attacker has gained information about what the user is doing at that time.
By correlating this with the applications the user is running, an attacker
could potentially discover what a user's actions are. From this, higher
levels of security could be breached.
Time of Introduction
Architecture and Design
Implementation
Applicable Platforms
Languages
All
Common Consequences
Scope
Effect
Confidentiality
Since the file is visible and the application which is using the temp
file could be known, the attacker has gained information about what the
user is doing at that time.
Likelihood of Exploit
Low
Demonstrative Examples
Example 1
(Bad Code)
C and C++
FILE *stream; char tempstring[] = "String to be written";
if( (stream = tmpfile()) == NULL ) {
perror("Could not open new temporary file\n");
return (-1);
}
/* write data to tmp file */
/* ... */
_rmtmp();
In cygwin and some older unixes one can ls /tmp and see that this temp
file exists.
Description
