CVE-2023-4759 : Exploit Details and Defense Strategies

This CVE-2023-4759 was published by Eclipse on September 12, 2023. The vulnerability involves arbitrary file overwriting in Eclipse JGit versions up to 6.6.0, allowing remote code execution via symbolic links in specially crafted git repositories.

Understanding CVE-2023-4759

This vulnerability in Eclipse JGit allows malicious actors to exploit a symbolic link present in a git repository to write files outside the working tree. This can lead to remote code execution on case-insensitive filesystems like those on Windows and macOS.

What is CVE-2023-4759?

In Eclipse JGit versions <= 6.6.0, a specially crafted git repository can be used to write files outside the working tree when cloned with JGit. This issue arises on case-insensitive filesystems during checkout, merge, pull, and patch application, potentially enabling remote code execution.

The Impact of CVE-2023-4759

The impact of this vulnerability, known as CAPEC-132 Symlink Attack, is rated as HIGH across confidentiality, integrity, and availability aspects. It requires user interaction and can be exploited by attackers without any special privileges.

Technical Details of CVE-2023-4759

The vulnerability stems from improper handling of case sensitivity in Eclipse JGit, allowing the creation of symbolic links that can lead to arbitrary file overwriting. It affects Eclipse JGit versions up to 6.6.0.

Vulnerability Description

The issue arises from the use of symbolic links in git repositories, which, when processed by JGit on case-insensitive filesystems, can write files outside the intended working directory.

Affected Systems and Versions

Eclipse JGit up to version 6.6.0.202305301015-r is impacted by this vulnerability, while versions after 6.6.1.202309021850-r have addressed the issue. An earlier backport is available in version 5.13.3.202401111512-r.

Exploitation Mechanism

The exploit occurs when a symbolic link in a git repository is used during operations like checkout, merge, pull, or patch application on case-insensitive filesystems, leading to file overwriting and potential remote code execution.

Mitigation and Prevention

To mitigate the CVE-2023-4759 vulnerability in Eclipse JGit, users are advised to take immediate steps and adopt long-term security practices to prevent potential exploitation.

Immediate Steps to Take

Setting the git configuration option

core.symlinks = false

before checking out can help avoid the problem and minimize the risk of arbitrary file overwriting in Eclipse JGit.

Long-Term Security Practices

Maintaining up-to-date software versions, monitoring security advisories, and implementing secure coding practices can enhance the overall security posture against such vulnerabilities.

Patching and Updates

Users are recommended to update their Eclipse JGit installations to versions 6.6.1.202309021850-r and 6.7.0.202309050840-r to address the CVE-2023-4759 vulnerability. Additionally, a backport fix is available in version 5.13.3.202401111512-r to provide protection against this exploitation.

By applying these mitigation strategies and staying informed about security updates, organizations can safeguard their systems against potential risks associated with CVE-2023-4759 in Eclipse JGit.