Description
Git is a revision control system. Prior to versions 2.45.1, 2.44.1, 2.43.4, 2.42.2, 2.41.1, 2.40.2, and 2.39.4, repositories with submodules can be crafted in a way that exploits a bug in Git whereby it can be fooled into writing files not into the submodule's worktree but into a `.git/` directory. This allows writing a hook that will be executed while the clone operation is still running, giving the user no opportunity to inspect the code that is being executed. The problem has been patched in versions 2.45.1, 2.44.1, 2.43.4, 2.42.2, 2.41.1, 2.40.2, and 2.39.4. If symbolic link support is disabled in Git (e.g. via `git config --global core.symlinks false`), the described attack won't work. As always, it is best to avoid cloning repositories from untrusted sources.
EPSS Score:
67%
Comprehensive Technical Analysis of EUVD-2024-29843
1. Vulnerability Assessment and Severity Evaluation
Vulnerability Description:
The vulnerability affects Git, a widely-used revision control system. Prior to specific versions, Git is susceptible to a bug where crafted repositories with submodules can manipulate Git into writing files into the .git/ directory instead of the submodule's worktree. This allows the execution of hooks during the clone operation, bypassing user inspection.
Severity Evaluation:
- CVSS Base Score: 9.1
- CVSS Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
The high base score indicates a critical vulnerability. The attack complexity (AC:H) is high, but the impact on confidentiality, integrity, and availability (C:H/I:H/A:H) is severe. The attack vector is network-based (AV:N), and no user interaction (UI:N) or privileges (PR:N) are required.
2. Potential Attack Vectors and Exploitation Methods
Attack Vectors:
- Malicious Repositories: Attackers can craft repositories with submodules designed to exploit the vulnerability.
- Supply Chain Attacks: Compromising upstream repositories or dependencies can propagate the vulnerability downstream.
Exploitation Methods:
- Hook Execution: By manipulating the submodule structure, attackers can write hooks into the
.git/directory, which will be executed during the clone operation. - Code Injection: The hooks can contain malicious code that executes arbitrary commands on the victim's system.
3. Affected Systems and Software Versions
Affected Versions:
- Git versions prior to 2.45.1, 2.44.1, 2.43.4, 2.42.2, 2.41.1, 2.40.2, and 2.39.4.
Systems at Risk:
- Any system using the affected Git versions, including development environments, CI/CD pipelines, and version control systems.
4. Recommended Mitigation Strategies
Immediate Mitigations:
- Update Git: Upgrade to the patched versions: 2.45.1, 2.44.1, 2.43.4, 2.42.2, 2.41.1, 2.40.2, or 2.39.4.
- Disable Symbolic Links: Configure Git to disable symbolic link support using
git config --global core.symlinks false.
Long-Term Mitigations:
- Repository Validation: Implement strict validation and inspection processes for repositories, especially those from untrusted sources.
- Code Review: Enforce rigorous code review practices to detect and mitigate potential vulnerabilities.
5. Impact on European Cybersecurity Landscape
Potential Impact:
- Widespread Adoption: Given Git's widespread use in software development, the vulnerability poses a significant risk to European organizations.
- Supply Chain Risks: The vulnerability can be exploited in supply chain attacks, affecting multiple downstream projects and organizations.
- Compliance Issues: Organizations may face compliance issues if they fail to address the vulnerability, especially in regulated industries.
Mitigation Efforts:
- Coordinated Response: European cybersecurity agencies and organizations should coordinate efforts to patch systems and raise awareness.
- Regulatory Compliance: Ensure compliance with relevant regulations and standards, such as GDPR and NIS Directive.
6. Technical Details for Security Professionals
Technical Overview:
- Submodule Manipulation: The vulnerability involves manipulating the submodule structure to write files into the
.git/directory. - Hook Execution: The written hooks can execute arbitrary commands, allowing attackers to gain control over the victim's system.
Detection and Response:
- Monitoring: Implement monitoring for suspicious activities related to Git operations, such as unexpected hook executions.
- Incident Response: Develop and test incident response plans to quickly address any detected exploitation attempts.
References:
- GitHub Advisory: GHSA-8h77-4q3w-gfgv
- Git Commit: 97065761333fd62db1912d81b489db938d8c991d
- Documentation:
Additional Resources:
- Fedora Announcement: Package Announce
- Openwall Discussion: OSS Security
- Debian Announcement: Debian LTS Announce
By addressing this vulnerability promptly and comprehensively, organizations can mitigate the risks associated with EUVD-2024-29843 and ensure the security of their development environments.