Magento Long Term Support (LTS) is an unofficial, community-driven project provides an alternative to the Magento Community Edition e-commerce platform with a high level of backward compatibility. Prior to version 20.17.0, PHP functions such as `getimagesize()`, `file_exists()`, and `is_readable()` can trigger deserialization when processing `phar://` stream wrapper paths. OpenMage LTS uses these functions with potentially controllable file paths during image validation and media handling. An attacker who can upload a malicious phar file (disguised as an image) and trigger one of these functions with a `phar://` path can achieve arbitrary code execution. Version 20.17.0 patches the issue.

Affected: Packagist: openmage/magento-lts

PHP functions such as `getimagesize()`, `file_exists()`, and `is_readable()` can trigger deserialization when processing `phar://` stream wrapper paths. OpenMage LTS uses these functions with potentially controllable file paths during image validation and media handling. An attacker who can upload a malicious phar file (disguised as an image) and trigger one of these functions with a `phar://` path can achieve arbitrary code execution.

| Metric | Value | Justification | | ------------------------ | --------- | ------------------------------------------------ | | Attack Vector (AV) | Network | Exploitable via file upload and web requests | | Attack Complexity (AC) | High | Requires file upload + triggering phar:// access | | Privileges Required (PR) | None | Some upload vectors don't require authentication | | User Interaction (UI) | None | Exploitation is automatic once triggered | | Scope (S) | Unchanged | Impacts the vulnerable component | | Confidentiality (C) | High | Full system access via RCE | | Integrity (I) | High | Arbitrary code execution | | Availability (A) | High | Complete system compromise possible |

## Affected Products

- OpenMage LTS versions < 20.16.1 - All versions derived from Magento 1.x with these code paths

## Affected Files…