CWE-64: Windows Shortcut Following (.LNK)

Description

The product, 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 product 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.

ThreatScore

Threat Mapped score: 0.0

Industry: Finiancial

Threat priority: Unclassified

Observed Examples (CVEs)

CVE: CVE-2019-19793

network access control service executes program with high privileges and allows symlink to invoke another executable or perform DLL injection.
CVE: CVE-2000-0342

Mail client allows remote attackers to bypass the user warning for executable attachments such as .exe, .com, and .bat by using a .lnk file that refers to the attachment, aka "Stealth Attachment."
CVE: CVE-2001-1042

FTP server allows remote attackers to read arbitrary files and directories by uploading a .lnk (link) file that points to the target file.
CVE: CVE-2001-1043

FTP server allows remote attackers to read arbitrary files and directories by uploading a .lnk (link) file that points to the target file.
CVE: CVE-2005-0587

Browser allows remote malicious web sites to overwrite arbitrary files by tricking the user into downloading a .LNK (link) file twice, which overwrites the file that was referenced in the first .LNK file.
CVE: CVE-2001-1386

".LNK." - .LNK with trailing dot
CVE: CVE-2003-1233

Rootkits can bypass file access restrictions to Windows kernel directories using NtCreateSymbolicLinkObject function to create symbolic link

Related Attack Patterns (CAPEC)

N/A

Attack TTPs

N/A

Modes of Introduction

Phase	Note
Operation	N/A

Common Consequences

Impact: Read Files or Directories, Modify Files or Directories — Notes:

Potential Mitigations

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. (N/A)

Applicable Platforms

None (Not Language-Specific, Undetermined)

Demonstrative Examples

N/A

Notes

Research Gap: 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.

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