CVE-2025-6278

The Path Traversal vulnerability in Upsonic allows an attacker to bypass intended access controls and read arbitrary files on the server. By manipulating the file.filename parameter, an attacker can construct file paths that escape the intended directory structure. This could lead to the exposure of sensitive data such as configuration files, source code, or even user data. Successful exploitation could also enable an attacker to modify or delete files, leading to a denial of service or further compromise of the system. The public disclosure of this vulnerability significantly increases the likelihood of exploitation.

Organizations using Upsonic for content management or data processing, particularly those running versions prior to 0.56.0, are at significant risk. Shared hosting environments where multiple users share the same server instance are especially vulnerable, as a compromise of one user's account could lead to access to other users' data.

• python / server:

import os
import hashlib

def check_upsonic_vulnerability(filename):
  # Simulate the vulnerable function
  filepath = os.path.join('markdown', filename)
  if '..' in filename:
    return True  # Path traversal detected
  return False

# Example usage
filename = input("Enter filename: ")
if check_upsonic_vulnerability(filename):
  print("Potential Path Traversal Vulnerability Detected!")
else:
  print("No Path Traversal Detected.")

• generic web:

curl -I 'http://your-upsonic-server/markdown/../../../../etc/passwd' # Check for directory traversal

1. 2025-06-19Disclosure

   disclosure

1. Gereserveerd2025-06-19
2. Gepubliceerd2025-06-19
3. Gewijzigd2025-07-09
4. EPSS bijgewerkt2026-03-23

The primary mitigation for CVE-2025-6278 is to upgrade Upsonic to version 0.56.0 or later, which contains the fix. If upgrading immediately is not possible, consider implementing temporary workarounds. Restrict file upload locations and implement strict input validation on the file.filename parameter to prevent path traversal attempts. Web Application Firewalls (WAFs) can be configured to block requests containing suspicious path traversal patterns. Monitor system logs for unusual file access attempts and implement intrusion detection signatures to identify potential exploitation.