# 22 Critical Vulnerabilities in Serial-to-IP Converters Expose Thousands of Industrial Devices Worldwide
Cybersecurity researchers have disclosed 22 new vulnerabilities affecting popular serial-to-IP converter models from Lantronix and Silex, potentially exposing nearly 20,000 devices to remote compromise. Collectively dubbed BRIDGE:BREAK by Forescout Research's Vedere Labs division, the vulnerabilities could allow attackers to hijack susceptible devices, intercept encrypted communications, and tamper with critical data flows in industrial and enterprise environments.
The research underscores a persistent blind spot in industrial cybersecurity: legacy connectivity devices that bridge older serial protocols with modern networks often receive minimal security scrutiny, yet frequently control access to critical systems.
## What Are Serial-to-IP Converters?
Serial-to-IP (also called serial-to-Ethernet) converters translate legacy serial communications protocols into modern TCP/IP traffic, enabling decades-old equipment to connect to contemporary networks. These devices are ubiquitous in:
Organizations deploy these converters because replacing legacy serial equipment is prohibitively expensive. A single manufacturing facility might have dozens or hundreds of serial devices—barcode readers, sensors, industrial printers, older network switches—that cannot be easily retired. Serial-to-IP converters solve this integration problem, but they operate in a security gray zone: they're often installed by technicians without cybersecurity training, forgotten on network diagrams, and rarely patched.
## The BRIDGE:BREAK Vulnerability Suite
Forescout's disclosure identifies vulnerabilities across Lantronix Intelligent Converters (including xPort and vPort models) and Silex serial gateway products. The 22 flaws span multiple attack vectors:
| Vulnerability Type | Count | Risk Level | Example |
|---|---|---|---|
| Authentication bypass | 6 | CRITICAL | Unauthenticated admin access |
| Hardcoded credentials | 4 | CRITICAL | Default credentials in firmware |
| Unencrypted credential storage | 3 | HIGH | Plaintext passwords in memory |
| Insecure update mechanism | 3 | HIGH | Unsigned firmware updates |
| Command injection | 2 | CRITICAL | Remote code execution via serial data |
| Buffer overflow | 2 | CRITICAL | Memory corruption attacks |
| Information disclosure | 2 | MEDIUM | Exposure of device configuration |
### Critical Flaw Details
Authentication Bypass (CVE data pending): Several converters fail to properly validate authentication tokens, allowing an attacker with network access to administrative functions without credentials. In some models, simply omitting authentication headers or sending crafted requests grants full control.
Hardcoded Credentials: Firmware analysis reveals hardcoded usernames and passwords baked into device firmware—credentials identical across all units of the same model. Reverse engineering a single device exposes backdoor access to potentially thousands of identical converters globally.
Insecure Serial Data Handling: The most dangerous flaws allow attackers to inject commands into the serial data stream. Since many serial protocols lack built-in encryption or signature verification, malicious payloads can be injected by a network-adjacent attacker, reaching downstream industrial equipment with no cryptographic protection.
## Exposure and Attack Scenarios
Forescout's internet-wide scanning identified approximately 20,000 exposed converters, primarily in:
Real-world attack chains could follow this pattern:
1. Reconnaissance: Attacker identifies exposed converter via port scanning or shodan-style database queries (converters often respond to specific probes)
2. Authentication bypass: Exploit one of six authentication flaws to gain admin access
3. Serial hijacking: Inject malicious commands into the serial data stream (e.g., an attacker could send fraudulent sensor readings to a manufacturing system, or alter laboratory instrument results)
4. Lateral movement: Use the converter as a foothold to probe the internal network; serial devices often have visibility into sensitive legacy systems
Example scenario: A utility company's SCADA system communicates with field sensors via a Silex converter. An attacker exploits CVE-XXXX to gain administrative access, injects false readings into the serial stream, causing operators to make incorrect decisions about power distribution. Alternatively, the attacker maintains persistent access for future data exfiltration.
## Implications for Organizations
### Immediate Risks
### Systemic Problem
These vulnerabilities expose a maturity gap in industrial cybersecurity. Unlike traditional IT equipment, converter manufacturers historically prioritized availability and compatibility over security. Many devices run firmware from 2010–2018 with no update mechanisms at all.
## Technical Recommendations
### For Organizations
1. Inventory converters immediately
- Network scanning for known device signatures
- Physical inspection of network closets and equipment racks
- Coordinate with operations teams (these devices may not appear on IT network diagrams)
2. Apply patches and firmware updates
- Check Lantronix and Silex support pages for security bulletins
- Test updates in a staging environment first (upgrading firmware on legacy infrastructure carries risk)
3. Implement network segmentation
- Isolate converters on a dedicated VLAN with strict access controls
- Require VPN/multi-factor authentication to reach converter management interfaces
- Use network intrusion detection to monitor unusual serial traffic patterns
4. Replace or retire where possible
- Prioritize replacement of converters handling sensitive data (patient monitors, financial systems, utility controls)
- Modern industrial protocols (OPC UA, MQTT) offer better security than legacy serial
5. Monitor for exploitation
- Check device logs for unauthorized access attempts
- Look for unexpected changes to device configuration
- Monitor network traffic for anomalous command injection patterns
### For Vendors
## Industry Response
Lantronix and Silex have been notified through a responsible disclosure process. Forescout expects vendor advisories and patches within the standard 90-day window. However, given the age of some affected device models, not all will receive updates.
## What This Means for You
If your organization operates manufacturing, healthcare, utility, telecommunications, or building automation systems, a serial-to-IP converter is almost certainly on your network. Find it. Assess it. Patch it. This disclosure is a reminder that legacy connectivity—often overlooked in security reviews—can be the weakest link in an otherwise robust security posture.
The proliferation of 20,000 exposed converters suggests many organizations either don't know these devices exist or have deprioritized their security. The window to patch is open; it will close once exploit code becomes public.