Creation of Temporary File in Directory with Insecure Permissions

Opis

The product creates a temporary file in a directory whose permissions allow unintended actors to determine the file's existence or otherwise access that file.

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.

Skutki

• Confidentiality

  Read Application Data

  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.

Zapobieganie

• Requirements

  Many contemporary languages have functions which properly handle this condition. Older C temp file functions are especially susceptible.

• Implementation

  Try to store sensitive tempfiles in a directory which is not world readable -- i.e., per-user directories.

• Implementation

  Avoid using vulnerable temp file functions.

Przykłady podatności

• CVE-2022-27818 A hotkey daemon written in Rust creates a domain socket file underneath /tmp, which is accessible by any user.
• CVE-2021-41989 analytic platform's repair functionality uses the %TEMP% folder of a user while running with higher privileges
• CVE-2021-21290 A Java-based application for a rapid-development framework uses File.createTempFile() to create a random temporary file with insecure default permissions.

Słabość nadrzędna

• CWE-377 Insecure Temporary File

Kiedy powstaje

• Implementation

Dotyczy

Not Language-Specific

Źródła

1. The CLASP Application Security Process — Secure Software, Inc., 2005
2. The Art of Software Security Assessment — Mark Dowd, John McDonald, Justin Schuh, Chapter 9, "Temporary Files", Page 538, Addison Wesley, 2006