CVE-2024-6829: Aimstack Aim Path Traversal Vulnerability

CVE-2024-6829 Overview

A critical path traversal vulnerability exists in aimhubio/aim version 3.19.3 that allows an attacker to exploit the tarfile.extractall() function to extract the contents of a maliciously crafted tarfile to arbitrary locations on the host server. The attacker can control repo.path and run_hash to bypass directory existence checks and extract files to unintended locations, potentially overwriting critical files. This can lead to arbitrary data being written to arbitrary locations on the remote tracking server, which could be used for further attacks such as writing a new SSH key to the target server.

Critical Impact

Remote attackers can achieve arbitrary file write on target systems, enabling potential server takeover through mechanisms such as SSH key injection or overwriting critical system files.

Affected Products

• Aimstack Aim version 3.19.3
• Python package aimstack:aim
• Remote tracking server deployments running vulnerable versions

Discovery Timeline

• 2025-03-20 - CVE CVE-2024-6829 published to NVD
• 2025-07-23 - Last updated in NVD database

Technical Details for CVE-2024-6829

Vulnerability Analysis

This vulnerability stems from unsafe handling of tarfile extraction operations in the Aim experiment tracking framework. The tarfile.extractall() function in Python is known to be dangerous when used with untrusted tar archives, as it does not perform adequate path validation by default.

In the vulnerable code path, an attacker can manipulate the repo.path and run_hash parameters to bypass directory existence checks that should restrict where files are extracted. This allows the extraction of specially crafted tar archives to arbitrary filesystem locations on the server hosting the Aim tracking service.

The attack surface is particularly concerning because Aim is designed to be a remote tracking server for machine learning experiments, meaning it's often exposed to network connections from multiple clients.

Root Cause

The root cause is classified as CWE-73 (External Control of File Name or Path). The application fails to properly sanitize or validate user-controlled input (repo.path and run_hash) before using these values in file system operations. Combined with the inherently unsafe nature of Python's tarfile.extractall() when used without the filter parameter (added in Python 3.12), this creates a path traversal condition.

The tarfile module in Python does not prevent extraction of files with absolute paths or path traversal sequences (e.g., ../) by default, allowing an attacker to craft a malicious tarfile that writes files outside the intended extraction directory.

Attack Vector

The attack is network-based and requires no authentication or user interaction, making it highly exploitable. An attacker can send a specially crafted tarfile to the vulnerable Aim tracking server with path traversal sequences embedded in the archived file paths. The attack proceeds as follows:

1. The attacker crafts a malicious tar archive containing files with traversal paths (e.g., ../../../../root/.ssh/authorized_keys)
2. The attacker manipulates repo.path and run_hash values to bypass any directory existence validation
3. When the server processes the archive using tarfile.extractall(), files are written to arbitrary locations
4. The attacker can leverage this to write SSH keys, overwrite configuration files, or plant malicious scripts for later execution

The vulnerability allows an attacker to achieve arbitrary file write on the target system, which can be escalated to remote code execution through various post-exploitation techniques. For detailed technical information, see the Huntr Bug Bounty Listing.

Detection Methods for CVE-2024-6829

Indicators of Compromise

• Unusual file modifications in system directories such as /root/.ssh/, /etc/, or other sensitive paths
• Tarfile extraction operations with path traversal sequences (../) in file paths
• Unexpected files appearing outside of the Aim repository directories
• Modified SSH authorized_keys files with unfamiliar public keys

Detection Strategies

• Monitor filesystem operations from the Aim service process for writes outside expected directories
• Implement file integrity monitoring (FIM) on critical system files and directories
• Review Aim server logs for unusual repository paths or run hash values
• Deploy web application firewalls (WAF) to detect path traversal patterns in incoming requests

Monitoring Recommendations

• Enable detailed logging for all tarfile extraction operations in the Aim service
• Set up alerts for any file modifications in /root/.ssh/, /etc/cron.d/, and other sensitive directories by the Aim process
• Monitor for new network connections originating from the server that could indicate post-exploitation activity
• Implement anomaly detection for the Aim service's file system access patterns

How to Mitigate CVE-2024-6829

Immediate Actions Required

• Upgrade Aimstack Aim to the latest patched version if available
• Restrict network access to the Aim tracking server to trusted clients only
• Implement additional file system access controls to limit the Aim service's write permissions
• Review the server for any signs of compromise if the vulnerable version was publicly accessible

Patch Information

Users should check the official Aimstack repository for security updates addressing this vulnerability. The Huntr Bug Bounty Listing contains additional details about the disclosure. Until a patch is available, apply the workarounds described below.

Workarounds

• Run the Aim service in a containerized environment with restricted filesystem access
• Use Python 3.12+ which includes the filter parameter for tarfile.extractall() to enable safer extraction modes
• Implement a reverse proxy with strict input validation in front of the Aim service
• Deploy the service with minimal filesystem permissions using a dedicated service account

# Configuration example - Run Aim in a restricted container
docker run --read-only \
  --tmpfs /tmp:rw,noexec,nosuid \
  -v /restricted/aim/data:/aim:rw \
  --security-opt=no-new-privileges:true \
  --cap-drop=ALL \
  aim-container:latest