CVE-2019-25502
📋 TL;DR
Simple Job Script contains a reflected cross-site scripting vulnerability in the job_type_value parameter that allows unauthenticated attackers to inject malicious SVG payloads. When victims visit crafted URLs, arbitrary JavaScript executes in their browsers, potentially stealing session cookies or performing unauthorized actions. Any system running vulnerable versions of Simple Job Script is affected.
💻 Affected Systems
- Simple Job Script
📦 What is this software?
Simplejobscript by Simplejobscript
⚠️ Risk & Real-World Impact
Worst Case
Attackers steal administrator session cookies, gain full administrative access to the application, and compromise the entire system or pivot to internal networks.
Likely Case
Attackers steal user session cookies to hijack accounts, perform unauthorized actions, or deploy malware through the victim's browser.
If Mitigated
With proper input validation and output encoding, malicious scripts are neutralized before reaching victim browsers, preventing exploitation.
🎯 Exploit Status
Exploit requires crafting a malicious URL with SVG payload in the job_type_value parameter and tricking victims into clicking it.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Unknown specific version - check vendor advisory
Vendor Advisory: Not provided in references
Restart Required: No
Instructions:
1. Check for updated version from Simple Job Script vendor
2. Apply the patch that implements proper input validation and output encoding
3. Test the fix by attempting to inject malicious scripts
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side validation to reject or sanitize job_type_value parameter containing SVG or script tags
Implement regex filter: /<\/?svg[^>]*>/i and /<\/?script[^>]*>/i
Content Security Policy
allImplement CSP headers to restrict script execution sources
Add header: Content-Security-Policy: script-src 'self'
🧯 If You Can't Patch
- Implement WAF rules to block requests containing SVG or JavaScript in job_type_value parameter
- Restrict access to jobs endpoint to authenticated users only
🔍 How to Verify
Check if Vulnerable:
Test by accessing /jobs endpoint with job_type_value parameter containing <svg onload=alert('XSS')> and check if script executesCheck Version:
Check application version in admin panel or configuration filesVerify Fix Applied:
Attempt the same test payload and verify script does not execute and input is properly sanitized📡 Detection & Monitoring
Log Indicators:
- HTTP requests to /jobs with job_type_value containing SVG or script tags
- Unusual parameter values in job_type_value field
Network Indicators:
- HTTP requests with SVG payloads in URL parameters
- Multiple requests to same endpoint with varying job_type_value parameters
SIEM Query:
source="web_logs" AND uri_path="/jobs" AND (param="job_type_value" AND value MATCHES "<svg|<script")