Description

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.

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. /etc/passwd). When the process opens the file, the attacker can assume the privileges of that process.

---

ThreatScore

Threat Mapped score: 0.0

Industry: Finiancial

Threat priority: Unclassified

---

Observed Examples (CVEs)

• CVE: CVE-2001-1494

  Hard link attack, file overwrite; interesting because program checks against soft links

• CVE: CVE-2002-0793

  Hard link and possibly symbolic link following vulnerabilities in embedded operating system allow local users to overwrite arbitrary files.

• CVE: CVE-2003-0578

  Server creates hard links and unlinks files as root, which allows local users to gain privileges by deleting and overwriting arbitrary files.

• CVE: CVE-1999-0783

  Operating system allows local users to conduct a denial of service by creating a hard link from a device special file to a file on an NFS file system.

• CVE: CVE-2004-1603

  Web hosting manager follows hard links, which allows local users to read or modify arbitrary files.

• CVE: CVE-2004-1901

  Package listing system allows local users to overwrite arbitrary files via a hard link attack on the lockfiles.

• CVE: CVE-2005-0342

  The Finder in Mac OS X and earlier allows local users to overwrite arbitrary files and gain privileges by creating a hard link from the .DS_Store file to an arbitrary file.

• CVE: CVE-2005-1111

  Hard link race condition

• CVE: CVE-2021-21272

  "Zip Slip" vulnerability in Go-based Open Container Initiative (OCI) registries product allows writing arbitrary files outside intended directory via symbolic links or hard links in a gzipped tarball.

• CVE: CVE-2003-1366

  setuid root tool allows attackers to read secret data by replacing a temp file with a hard link to a sensitive file

Related Attack Patterns (CAPEC)

N/A

---

Attack TTPs

N/A

Modes of Introduction

Phase	Note
Implementation	N/A

Common Consequences

Potential Mitigations

Applicable Platforms

• None (Not Language-Specific, Undetermined)

---

Demonstrative Examples

N/A

Notes

← Back to CWE list