CVE-2025-29156
📋 TL;DR
A cross-site scripting (XSS) vulnerability in petstore v1.0.7 allows remote attackers to inject malicious scripts via the /api/v3/pet endpoint. This could enable attackers to execute arbitrary JavaScript in users' browsers, potentially stealing session cookies or performing actions on behalf of authenticated users. Any system running the vulnerable petstore version with the affected API endpoint exposed is at risk.
💻 Affected Systems
- petstore
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, take over accounts, deface websites, or redirect users to malicious sites, potentially leading to complete system compromise if combined with other vulnerabilities.
Likely Case
Attackers steal user session cookies or authentication tokens, leading to account takeover and unauthorized access to sensitive pet store data.
If Mitigated
With proper input validation and output encoding, malicious scripts are neutralized, preventing execution in users' browsers.
🎯 Exploit Status
Exploitation requires crafting malicious scripts and delivering them through the vulnerable endpoint, typically requiring some user interaction or specific conditions.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: v1.0.8 or later
Vendor Advisory: https://github.com/swagger-api/swagger-petstore
Restart Required: No
Instructions:
1. Check current version with appropriate package manager command. 2. Update to v1.0.8 or later using your package manager. 3. Verify the update was successful. 4. Test the /api/v3/pet endpoint with XSS payloads to confirm fix.
🔧 Temporary Workarounds
Input Validation Filter
allImplement server-side input validation to sanitize or reject malicious script content in API requests.
Implement input validation middleware that strips or encodes <script> tags and JavaScript event handlers
Output Encoding
allApply proper output encoding when displaying user-supplied data to prevent script execution.
Use HTML entity encoding for user-controlled data displayed in web pages
🧯 If You Can't Patch
- Implement a web application firewall (WAF) with XSS protection rules
- Restrict access to the /api/v3/pet endpoint to trusted IP addresses only
🔍 How to Verify
Check if Vulnerable:
Test the /api/v3/pet endpoint with XSS payloads like <script>alert('XSS')</script> and check if scripts execute in browser.Check Version:
Check package.json or application metadata for version informationVerify Fix Applied:
After patching, retest with the same XSS payloads to confirm scripts no longer execute.📡 Detection & Monitoring
Log Indicators:
- Unusual POST requests to /api/v3/pet containing script tags or JavaScript code
- Multiple failed attempts with suspicious payloads
Network Indicators:
- HTTP requests to /api/v3/pet with encoded script content in parameters
SIEM Query:
source="web_server" AND (uri="/api/v3/pet" AND (body CONTAINS "<script>" OR body CONTAINS "javascript:"))