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PatchSiren cyber security CVE debrief

CVE-2024-3741 Electrolink CVE debrief

CVE-2024-3741 is a HIGH severity authentication bypass vulnerability in Electrolink FM/DAB/TV transmitters, published on 2024-04-16. The vulnerability stems from improper session validation in the login cookie mechanism: an attacker can set an arbitrary value (any value except 'NO') to the login cookie to gain full system access without valid credentials. This represents a critical weakness in session management where the application fails to properly validate authentication state, allowing trivial privilege escalation. The CVSS 3.1 score of 7.5 reflects network attack vector, low attack complexity, no privileges required, and high impact to integrity. Notably, Electrolink has not responded to CISA coordination requests, leaving affected users without vendor-supplied mitigations. The broad product scope—24 transmitter models across DAB, FM, and TV broadcast equipment—suggests significant exposure in critical broadcast infrastructure.

Vendor
Electrolink
Product
10W Compact DAB Transmitter
CVSS
HIGH 7.5
CISA KEV
Not listed in stored evidence
Original CVE published
2024-04-16
Original CVE updated
2024-04-16
Advisory published
2024-04-16
Advisory updated
2024-04-16

Who should care

Broadcast operators, critical infrastructure security teams, media organizations, and OT security practitioners managing Electrolink transmission equipment should prioritize assessment and compensating controls.

Technical summary

The vulnerability exists in the login cookie validation logic of Electrolink transmitter management interfaces. The application checks whether the login cookie equals 'NO' to determine unauthenticated state; any other value—including arbitrary strings—is treated as authenticated. This flawed boolean-equivalent check allows attackers to forge session credentials without knowledge of valid credentials or session tokens. The attack requires network access to the management interface (typically HTTP/HTTPS) and can be executed with standard HTTP client tools. No user interaction or prior authentication is required.

Defensive priority

critical

Recommended defensive actions

  • Contact Electrolink directly for security updates or alternative mitigation guidance
  • Implement network segmentation to isolate affected transmitters from untrusted networks
  • Deploy web application firewalls or reverse proxies with strict cookie validation rules
  • Monitor for anomalous cookie values in HTTP requests to transmitter management interfaces
  • Apply CISA ICS recommended practices for defense-in-depth security controls
  • Consider disabling remote management interfaces where operational requirements permit

Evidence notes

Authentication bypass via login cookie manipulation; arbitrary non-'NO' value grants full access. Vendor unresponsive to CISA coordination.

Official resources

2024-04-16