Executive Summary
In April 2026, Forescout Technologies identified 22 vulnerabilities in serial-to-IP converters from Lantronix and Silex, devices integral to connecting legacy industrial equipment to modern networks. These vulnerabilities, collectively named BRIDGE:BREAK, could allow attackers to disrupt operations, move laterally across networks, tamper with sensitive data, or take control of affected devices. The flaws include remote code execution, authentication bypass, firmware manipulation, denial of service, and exposure of confidential information. Notably, tens of thousands of these devices are accessible over the internet, significantly broadening the attack surface for potential cyberattacks.
This discovery underscores the persistent security challenges in operational technology environments, especially concerning devices that bridge legacy systems with modern infrastructure. The prevalence of these vulnerabilities highlights the need for organizations to reassess their security postures, particularly in sectors like utilities, manufacturing, and healthcare, where such devices are commonly deployed.
Why This Matters Now
The BRIDGE:BREAK vulnerabilities expose critical infrastructure to potential cyberattacks, emphasizing the urgent need for organizations to secure operational technology devices that connect legacy systems to modern networks.
Attack Path Analysis
Attackers exploited vulnerabilities in exposed serial-to-IP converters to gain initial access, escalated privileges by exploiting authentication weaknesses, moved laterally through the network by compromising connected devices, established command and control channels via the compromised converters, exfiltrated sensitive data through these channels, and ultimately disrupted operations by tampering with device firmware.
Kill Chain Progression
Initial Compromise
Description
Attackers exploited vulnerabilities in exposed serial-to-IP converters to gain unauthorized access.
MITRE ATT&CK® Techniques
Exploitation of Remote Services
Block Serial COM
Bandwidth Hijacking
Wireless Sniffing
Wireless Compromise
Potential Compliance Exposure
Mapping incident impact across multiple compliance frameworks.
PCI DSS 4.0 – System and Application Security
Control ID: 6.2
NYDFS 23 NYCRR 500 – Cybersecurity Policy
Control ID: 500.03
DORA – ICT Risk Management Framework
Control ID: Article 5
CISA ZTMM 2.0 – Asset Management
Control ID: 3.1
NIS2 Directive – Security Requirements
Control ID: Article 21
Sector Implications
Industry-specific impact of the vulnerabilities, including operational, regulatory, and cloud security risks.
Utilities
Serial-to-IP converters critical for SCADA systems face vulnerability exploitation risks, potentially enabling lateral movement and exfiltration in operational technology networks.
Oil/Energy/Solar/Greentech
Energy infrastructure using Lantronix/Silex converters vulnerable to device hijacking and data tampering, compromising industrial automation and encrypted traffic security.
Industrial Automation
Manufacturing systems relying on serial-to-Ethernet converters exposed to 22 BRIDGE:BREAK vulnerabilities, risking operational disruption and zero trust segmentation failures.
Transportation
Transportation networks using affected serial converters face threat detection challenges and potential compromise of east-west traffic security in connected infrastructure.
Sources
- 22 BRIDGE:BREAK Flaws Expose 20,000 Lantronix and Silex Serial-to-IP Convertershttps://thehackernews.com/2026/04/22-bridgebreak-flaws-expose-20000.htmlVerified
- Serial-to-IP Converter Flaws Expose OT and Healthcare Systems to Hackinghttps://www.securityweek.com/serial-to-ip-converter-flaws-expose-ot-and-healthcare-systems-to-hacking/Verified
- Forescout Uncovers New Security Risks in Widely Used Industrial Networking Deviceshttps://www.itsecurityguru.org/2026/04/21/forescout-uncovers-new-security-risks-in-widely-used-industrial-networking-devices/Verified
- BRIDGE:BREAK: Forescout Identifies 22 New Vulnerabilities on Serial-to-IP Converters, and Finds Thousands Exposed Onlinehttps://www.streetinsider.com/Business%2BWire/BRIDGE%3ABREAK%3A%2BForescout%2BIdentifies%2B22%2BNew%2BVulnerabilities%2Bon%2BSerial-to-IP%2BConverters%2C%2Band%2BFinds%2BThousands%2BExposed%2BOnline/26340110.htmlVerified
Frequently Asked Questions
Cloud Native Security Fabric Mitigations and ControlsCNSF
Aviatrix Zero Trust CNSF is pertinent to this incident as it could have limited the attacker's ability to move laterally and exfiltrate data by enforcing strict segmentation and identity-aware routing, thereby reducing the blast radius of the compromise.
Control: Cloud Native Security Fabric (CNSF)
Mitigation: The attacker's initial access may have been constrained by limiting exposure of vulnerable devices through enforced segmentation.
Control: Zero Trust Segmentation
Mitigation: The attacker's ability to escalate privileges could have been limited by enforcing strict identity-aware access controls.
Control: East-West Traffic Security
Mitigation: The attacker's lateral movement would likely have been constrained by monitoring and controlling east-west traffic between workloads.
Control: Multicloud Visibility & Control
Mitigation: The attacker's command and control channels may have been detected and disrupted through enhanced visibility and control across multicloud environments.
Control: Egress Security & Policy Enforcement
Mitigation: The attacker's data exfiltration efforts could have been limited by enforcing strict egress policies and monitoring outbound traffic.
The attacker's ability to disrupt operations would likely have been reduced by limiting their access to critical devices and systems.
Impact at a Glance
Affected Business Functions
- Industrial Control Systems
- Healthcare Monitoring Systems
- Manufacturing Operations
- Utility Management
Estimated downtime: N/A
Estimated loss: N/A
Potential exposure of operational data in industrial and healthcare environments.
Recommended Actions
Key Takeaways & Next Steps
- • Implement Zero Trust Segmentation to restrict device communication paths and limit lateral movement.
- • Deploy East-West Traffic Security controls to monitor and control internal network traffic.
- • Utilize Multicloud Visibility & Control solutions to detect and respond to anomalous activities across environments.
- • Enforce Egress Security & Policy Enforcement to prevent unauthorized data exfiltration.
- • Regularly update and patch devices to mitigate known vulnerabilities.
