CVE-2024-51990 in martinvonz
Summary
by MITRE • 11/07/2024
jj, or Jujutsu, is a Git-compatible VCS written in rust. In affected versions specially crafted Git repositories can cause `jj` to write files outside the clone. This issue has been addressed in version 0.23.0. Users are advised to upgrade. Users unable to upgrade should avoid cloning repos from unknown sources.
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Analysis
by VulDB Data Team • 11/07/2024
The vulnerability identified as CVE-2024-51990 affects jj, a Git-compatible version control system written in rust that aims to provide a more robust and flexible alternative to traditional Git operations. This flaw represents a critical path traversal vulnerability that allows maliciously crafted Git repositories to exploit the cloning mechanism of jj, potentially enabling unauthorized file system modifications beyond the intended clone directory. The vulnerability specifically manifests when jj processes specially crafted repository structures that contain malicious file paths or symbolic links designed to bypass normal directory boundaries during the cloning process.
The technical implementation of this vulnerability stems from insufficient input validation and path sanitization within jj's repository cloning logic. When jj encounters repository metadata containing relative path traversal sequences such as ../ or symbolic links pointing to arbitrary locations on the file system, it fails to properly validate these paths before attempting to create files or directories. This behavior aligns with CWE-22, which describes improper limitation of a pathname to a restricted directory, commonly known as path traversal or directory traversal attacks. The flaw essentially allows an attacker to manipulate the file system by creating files outside the intended working directory, potentially leading to arbitrary code execution, data corruption, or privilege escalation depending on the target system's permissions.
The operational impact of this vulnerability extends beyond simple data integrity concerns to encompass significant security risks for users who may inadvertently clone repositories from untrusted sources. Attackers can craft malicious repositories that, when cloned using affected versions of jj, will execute file system operations outside the expected clone location, potentially overwriting critical system files or creating backdoor entries. This threat model particularly affects developers and security professionals who frequently clone repositories from various sources, as well as automated systems that may programmatically clone repositories without proper security screening. The vulnerability creates a persistent risk for any environment where jj is used for repository management, especially in collaborative development environments or automated CI/CD pipelines where repository cloning occurs without manual verification of source authenticity.
Organizations and individual users should prioritize upgrading to jj version 0.23.0 or later, which includes the necessary patches to address the path traversal vulnerability. The fix implemented in this release involves enhanced path validation mechanisms that properly sanitize repository metadata before file system operations are executed, ensuring that all file paths remain within the designated clone directory boundaries. For users unable to upgrade immediately, the recommended mitigation strategy involves implementing strict repository source verification practices, including manual inspection of repository contents, use of trusted repository sources, and implementation of automated scanning tools to detect potentially malicious repository structures. Additionally, security teams should consider implementing network-level controls to restrict access to untrusted repository sources and establish clear policies for repository cloning operations within their environments. The vulnerability demonstrates the importance of input validation in version control systems and highlights the need for robust security measures when handling external repository data, particularly in automated environments where such operations may occur without explicit user oversight.