CWE-62: UNIX Hard Link

What is CWE-62?

CWE-62 is UNIX Hard Link. The flaw arises when the product, when opening a file or directory, does not sufficiently account for when the name is associated with a hard link to a target that is outside of the intended control sphere. The database currently holds 2 vulnerabilities mapped to CWE-62 and none of them are in the CISA Known Exploited Vulnerabilities catalog.

OWASP Top 10 Rank-
Related CVES (365 days)2
AbstractionVariant
Likelihood of exploit-

Vulnerabilities mapped to CWE-62

2 vulnerabilitiesNo change year over year

No data

No vulnerability data in CISA KEV for CWE-62

Official definition

ByMitre CWE

The product, when opening a file or directory, does not sufficiently account for 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.

Characteristics

Modes of introduction

  • Implementation

Common consequences

ImpactScopeExplanation
Read Files or Directories, Modify Files or DirectoriesConfidentiality, IntegrityAn 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. /etc/passwd). When the process opens the file, the attacker can assume the privileges of that process.

Risk mitigations

  1. Separation of Privilege · Architecture and DesignFollow 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.

Representative vulnerabilities

Below are representative vulnerabilities related to this CWE, prioritized by severity.

Sources (2)
MITRE CWE
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