CWE-65 Windows Hard Link

The product, when opening a file or directory, does not sufficiently handle when the name is associated with a hard link to a target that is outside of the intended control sphere. This could allow an attacker to cause the product to operate on unauthorized files.

• Confidentiality, Integrity: Read Files or Directories, Modify Files or Directories — Failure for a system to check for hard links can result in vulnerability to different types of attacks. For example, an attacker can escalate their privileges if a file used by a privileged program is replaced with a hard link to a sensitive file (e.g. AUTOEXEC.BAT). When the process opens the file, the attacker can assume the privileges of that process, or prevent the program from accurately processing data.

• [Architecture and Design] Follow the principle of least privilege when assigning access rights to entities in a software system. Denying access to a file can prevent an attacker from replacing that file with a link to a sensitive file. Ensure good compartmentalization in the system to provide protected areas that can be trusted.

• CVE-2002-0725: Chain: File system allows local attackers to hide file usage activities via a hard link (CWE-65) to the target file, which causes the link to be recorded in the audit trail instead of the target file (CWE-221). • CVE-2003-0844: Web server plugin allows local users to overwrite arbitrary files via a symlink attack on predictable temporary filenames.