CVE-2025-52218
📋 TL;DR
CVE-2025-52218 is a content spoofing vulnerability in SelectZero Data Observability Platform that allows attackers to inject arbitrary text or limited HTML into the login page through improper input sanitization. This affects all users of SelectZero Data Observability Platform versions before 2025.5.2. Attackers can manipulate the login interface to display misleading information or phishing content.
💻 Affected Systems
- SelectZero Data Observability Platform
📦 What is this software?
Selectzero by Selectzero
⚠️ Risk & Real-World Impact
Worst Case
Attackers could inject phishing content or malicious links into the login page, potentially leading to credential theft, social engineering attacks, or redirecting users to malicious sites.
Likely Case
Attackers inject misleading text or basic HTML into the login page to display fake messages, warnings, or instructions that could confuse users or damage organizational reputation.
If Mitigated
With proper web application firewalls and input validation controls, injection attempts would be blocked, limiting the attack surface to only sophisticated bypass attempts.
🎯 Exploit Status
The vulnerability requires no authentication and involves simple parameter manipulation. No public exploit code has been identified yet.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2025.5.2
Vendor Advisory: https://selectzero.io/change-log/
Restart Required: Yes
Instructions:
1. Backup current configuration and data. 2. Download version 2025.5.2 from official SelectZero repository. 3. Stop the SelectZero service. 4. Install the updated version. 5. Restart the SelectZero service. 6. Verify the update by checking the version.
🔧 Temporary Workarounds
Web Application Firewall Rule
allImplement WAF rules to block suspicious parameter patterns and HTML injection attempts
# Example ModSecurity rule: SecRule ARGS "@rx <[^>]*>" "id:1001,phase:2,deny,msg:'HTML injection attempt'"
# Cloudflare WAF: Create rule blocking requests with suspicious parameter content
Input Validation Proxy
linuxDeploy a reverse proxy with input validation to sanitize parameters before reaching the application
# nginx configuration example: location /login { proxy_pass http://selectzero-backend; set $args "${args}"; # Add validation logic here }
🧯 If You Can't Patch
- Implement strict web application firewall rules to block HTML and script injection patterns in all parameters
- Restrict access to the login page using network segmentation and only allow trusted IP ranges
🔍 How to Verify
Check if Vulnerable:
Test by attempting to inject HTML tags or special characters into login page parameters and observing if they appear rendered in the responseCheck Version:
Check the SelectZero admin interface or run: selectzero --version or check the application's about/version endpointVerify Fix Applied:
After patching, repeat the injection tests to confirm that HTML/text injection no longer works and input is properly sanitized📡 Detection & Monitoring
Log Indicators:
- Unusual parameter values containing HTML tags or script elements in login requests
- Multiple failed login attempts with suspicious parameter content
- Requests with encoded HTML entities in parameters
Network Indicators:
- HTTP requests to login endpoint with unusual parameter lengths or content
- Traffic patterns showing repeated parameter manipulation attempts
SIEM Query:
source="selectzero" AND (uri_path="/login" OR uri_path="/auth") AND (param_value="*<*" OR param_value="*&*;*")