CVE-2021-37710
📋 TL;DR
This CVE describes a Cross-Site Scripting (XSS) vulnerability in Shopware eCommerce platform that allows attackers to inject malicious scripts via SVG media files. When exploited, this can lead to session hijacking, credential theft, or website defacement. All Shopware installations prior to version 6.4.3.1 are affected.
💻 Affected Systems
- Shopware
📦 What is this software?
Shopware by Shopware
⚠️ Risk & Real-World Impact
Worst Case
Complete account takeover, administrative privilege escalation, data exfiltration, and full compromise of the eCommerce platform and customer data.
Likely Case
Session hijacking, credential theft from users, website defacement, and potential malware distribution to visitors.
If Mitigated
Limited impact with proper input validation and output encoding, but still represents a security weakness.
🎯 Exploit Status
Exploitation requires an attacker to upload a malicious SVG file, which typically requires some level of access or social engineering. The vulnerability is well-documented in public advisories.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 6.4.3.1
Vendor Advisory: https://github.com/shopware/platform/security/advisories/GHSA-fc38-mxwr-pfhx
Restart Required: No
Instructions:
1. Backup your Shopware installation and database. 2. Update to Shopware version 6.4.3.1 or later. 3. Verify the update completed successfully. 4. Test media upload functionality.
🔧 Temporary Workarounds
Security Plugin for Older Versions
allFor Shopware 6.1, 6.2, and 6.3 versions, install the official security plugin that provides the same protection as the patch.
Download from Shopware store or GitHub and install via admin panel
Disable SVG Uploads
allTemporarily disable SVG file uploads in Shopware configuration until patching can be completed.
Modify Shopware configuration to restrict media uploads to non-SVG formats
🧯 If You Can't Patch
- Implement strict Content Security Policy (CSP) headers to mitigate XSS impact
- Deploy a Web Application Firewall (WAF) with XSS protection rules
🔍 How to Verify
Check if Vulnerable:
Check Shopware version in admin panel or via composer show shopware/platformCheck Version:
composer show shopware/platform | grep versionVerify Fix Applied:
Verify version is 6.4.3.1 or later, and test SVG upload functionality with malicious payloads📡 Detection & Monitoring
Log Indicators:
- Unusual SVG file uploads
- Multiple failed upload attempts
- Requests with suspicious SVG content
Network Indicators:
- Unusual traffic patterns to media upload endpoints
- Requests containing SVG with script tags
SIEM Query:
source="shopware.log" AND ("svg" AND ("script" OR "javascript" OR "onload"))🔗 References
- https://github.com/shopware/platform/commit/abe9f69e1f667800f974acccd3047b4930e4b423
- https://github.com/shopware/platform/security/advisories/GHSA-fc38-mxwr-pfhx
- https://github.com/shopware/platform/commit/abe9f69e1f667800f974acccd3047b4930e4b423
- https://github.com/shopware/platform/security/advisories/GHSA-fc38-mxwr-pfhx
