Ubuntu Package Security & Backporting Policy

This document outlines Webscale’s technical strategy for managing software packages

Core Strategy

Webscale utilizes official Ubuntu-packaged software for all core infrastructure components. While upstream developers frequently release new “mainline” versions with higher version numbers, Webscale prioritizes the stable versions maintained and vetted by Canonical (the publishers of Ubuntu).

The Backporting Mechanism

The primary reason for staying on a specific Ubuntu package version is the process of backporting.

  • Definition: Backporting is the practice of taking a specific security fix (CVE patch) from a newer version of software and applying it to an older, more stable version.
  • Canonical’s Role: Canonical’s security team monitors upstream vulnerabilities. When a vulnerability is found in a tool like Nginx, they apply the fix to the version of Nginx currently shipping with the Ubuntu LTS (Long Term Support) release.
  • Result: The version number of the package remains the same (e.g., 1.18.0), but the security posture is identical to the latest upstream version (e.g., 1.25.x).

Technical Comparison: Nginx Security Case Study

A common customer request is to upgrade to the latest “mainline” version of Nginx to address specific CVEs. The table below illustrates how Webscale/Ubuntu addresses these concerns:

Feature Upstream (Mainline) Ubuntu Package (LTS)
Version Number Incrementing (e.g., 1.25.x) Static (e.g., 1.18.x)
Security Fixes Included in new releases Backported into existing version
Stability Variable (new features may introduce bugs) High (only security/critical fixes applied)
Vetting Community-driven Rigorously tested by Canonical

Example: CVE-2024-1642

  • Upstream Fix: Resolved in Nginx 1.25.2.
  • Ubuntu Fix: The security patch was backported to the version of Nginx residing in the Ubuntu official repositories.
  • Stance: A system running the Ubuntu-provided version is as secure against this vulnerability as a system running Nginx 1.25.2, but with significantly higher architectural stability.

Key Benefits

  • Security Validation: Offloads the intensive task of patch validation and regression testing to Canonical.
  • Consistency: Ensures that the environment remains stable and predictable, as core library dependencies do not change unexpectedly.
  • Compliance: Official packages provide a clear audit trail for security compliance and vulnerability management.

Verification

To verify if a specific CVE has been addressed in an “older” Ubuntu package version, users can consult the official Ubuntu Security notices or check the package changelog locally:

apt-get changelog \<package-name\>



Last modified April 20, 2026