COMMON WEAKNESS ENUMERATIONIncomplete

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.

Abstraction

Variant

Structure

Simple

Likelihood of Exploit

Medium

Understand the problem

What is the problem?

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.

Extended description

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.

Root cause

How and when does the problem arise?

Lifecycle phase

Implementation

Lifecycle phase

Operation

Risk

What does successful exploitation lead to?

Read Files or DirectoriesModify Files or Directories

Affected security scopes: Confidentiality, Integrity

Defence

How is it prevented and fixed?

Architecture and Design

Separation of Privilege

Detail
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.