CVE-2024-25734
📋 TL;DR
This vulnerability allows remote attackers to enumerate valid user accounts on WyreStorm Apollo VX20 devices by observing TELNET service behavior. The service only prompts for a password after receiving a valid username, making it possible to identify existing accounts through brute-force or dictionary attacks. This affects all WyreStorm Apollo VX20 devices running firmware versions before 1.3.58.
💻 Affected Systems
- WyreStorm Apollo VX20
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could enumerate all valid user accounts, then use credential stuffing or brute-force attacks to gain unauthorized access, potentially leading to full device compromise and network infiltration.
Likely Case
Attackers will enumerate valid usernames, increasing the efficiency of subsequent password attacks and potentially gaining administrative access to the device.
If Mitigated
With proper network segmentation and access controls, the impact is limited to information disclosure about valid usernames without leading to system compromise.
🎯 Exploit Status
The vulnerability is simple to exploit using standard TELNET clients and username enumeration scripts. Public exploit details are available in the referenced disclosures.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 1.3.58
Vendor Advisory: Not provided in references
Restart Required: Yes
Instructions:
1. Download firmware version 1.3.58 from WyreStorm support portal. 2. Upload firmware to device via web interface. 3. Apply update and restart device. 4. Verify firmware version shows 1.3.58.
🔧 Temporary Workarounds
Disable TELNET Service
allDisable the TELNET service entirely if not required for operations
Access device web interface > Services > Disable TELNET
Network Access Control
allRestrict TELNET access to trusted IP addresses only
Configure firewall rules to block port 23 from untrusted networks
🧯 If You Can't Patch
- Implement strict network segmentation to isolate affected devices from untrusted networks
- Enable logging and monitoring of TELNET authentication attempts for suspicious activity
🔍 How to Verify
Check if Vulnerable:
Connect to device TELNET service (port 23) and attempt username enumeration by observing whether password prompt appears only after valid usernamesCheck Version:
Check device web interface or use SNMP query to verify firmware version is 1.3.58 or higherVerify Fix Applied:
After patching, verify that TELNET service no longer reveals valid usernames through differential response behavior📡 Detection & Monitoring
Log Indicators:
- Multiple failed TELNET authentication attempts with different usernames
- Successful username enumeration patterns
Network Indicators:
- Unusual TELNET traffic from external IPs
- Rapid sequential TELNET connection attempts
SIEM Query:
source_port:23 AND (event_type:authentication_failure OR event_type:connection_attempt) | stats count by src_ip