CVE-2015-3939: Directory traversal vulnerability in the NC854 and NC856 modules for IDS RTU 850C devices allows remote aut...

Security readout for executives and security teams

This issue could let someone who already has authenticated access to the IDS RTU 850C internal web server read files they should not see. The public description specifically mentions a TELNET credentials file, so the business concern is credential exposure on industrial remote terminal equipment. Exposure is most likely where IDS RTU 850C devices with NC854 or NC856 modules have the internal web server reachable by users or networks beyond tightly controlled operations staff. Treat this as high priority for environments using the affected RTU modules, especially in operational technology networks. The issue requires authenticated access, but successful abuse could expose credentials and support broader compromise of industrial systems. Mitigation focus: Check the IDS and CISA advisory for vendor-approved remediation or firmware guidance.; Restrict RTU internal web server access to trusted management networks only.; Review accounts with access to the RTU web interface..

Prepared

Jun 13, 2026, 22:39 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.