CVE-2025-4296
📋 TL;DR
An open redirect vulnerability in HotelRunner B2B allows attackers to redirect users to malicious websites by manipulating URLs. This affects HotelRunner B2B users before the June 4, 2025 update. The vulnerability enables forceful browsing attacks where users can be tricked into visiting untrusted sites.
💻 Affected Systems
- HotelRunner B2B
⚠️ Manual Verification Required
This CVE does not have specific version information in our database, so automatic vulnerability detection cannot determine if your system is affected.
Why? The CVE database entry doesn't specify which versions are vulnerable (no version ranges provided by the vendor/NVD).
🔒 Custom verification scripts are available for registered users. Sign up free to download automated test scripts.
- Review the CVE details at NVD
- Check vendor security advisories for your specific version
- Test if the vulnerability is exploitable in your environment
- Consider updating to the latest version as a precaution
⚠️ Risk & Real-World Impact
Worst Case
Users could be redirected to phishing sites that steal credentials or deliver malware, potentially leading to account compromise or system infection.
Likely Case
Attackers redirect users to phishing pages or malicious sites for credential harvesting or social engineering attacks.
If Mitigated
Users receive warnings about external redirects or are blocked from being redirected to untrusted domains.
🎯 Exploit Status
Open redirect vulnerabilities typically require minimal technical skill to exploit via crafted URLs.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version updated on or after 04.06.2025
Vendor Advisory: https://www.usom.gov.tr/bildirim/tr-25-0169
Restart Required: No
Instructions:
1. Update HotelRunner B2B to version dated 04.06.2025 or later. 2. Verify the update was applied successfully. 3. Test redirect functionality to ensure validation is working.
🔧 Temporary Workarounds
Input Validation at Web Server
allImplement URL validation at the web server or load balancer level to block redirects to external domains.
Content Security Policy
allImplement Content Security Policy headers to restrict which domains can be loaded or redirected to.
🧯 If You Can't Patch
- Implement WAF rules to detect and block open redirect patterns in URLs
- Monitor logs for suspicious redirect patterns and user reports of unexpected redirects
🔍 How to Verify
Check if Vulnerable:
Test by attempting to redirect to an external domain using the vulnerable endpoint/parameter. If redirect succeeds without validation, system is vulnerable.Check Version:
Check HotelRunner B2B admin panel or system information for version/date (should show 04.06.2025 or later)Verify Fix Applied:
Attempt the same redirect test after patching. Successful fix should block redirects to untrusted domains or require user confirmation.📡 Detection & Monitoring
Log Indicators:
- Unusual redirect patterns in web server logs
- Multiple requests with external domain parameters
- User reports of unexpected redirects
Network Indicators:
- HTTP 302/301 redirects to unexpected external domains
- Suspicious referrer headers
SIEM Query:
web_logs WHERE url CONTAINS 'redirect=' AND url CONTAINS 'http://' OR 'https://' AND NOT url CONTAINS 'trusted-domain.com'