The software, when opening a file or directory, does not
sufficiently handle when the file is a Windows shortcut (.LNK) whose target is
outside of the intended control sphere. This could allow an attacker to cause
the software to operate on unauthorized files.
Extended Description
The shortcut (file with the .lnk extension) can permit an attacker to
read/write a file that they originally did not have permissions to
access.
Rootkits can bypass file access restrictions to
Windows kernel directories using NtCreateSymbolicLinkObject function to
create symbolic link
Potential Mitigations
Phase
Description
Follow the principle of least privilege when assigning access rights
to files. 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.
Weakness Ordinalities
Ordinality
Description
Resultant
(where the
weakness is typically related to the presence of some other
weaknesses)
Weaknesses Addressed by the CERT C Secure Coding Standard (primary)734
Research Gaps
Under-studied. Windows .LNK files are more "portable" than Unix symlinks
and have been used in remote exploits. Some Windows API's will access LNK's
as if they are regular files, so one would expect that they would be
reported more frequently.
Description
