CVE-2014-2254: Siemens SIMATIC S7-1200 CPU PLC devices with firmware before 4.0 allow remote attackers to cause a denial o...

Security readout for executives and security teams

CVE-2014-2254 affects Siemens SIMATIC S7-1200 CPU PLCs running firmware before 4.0. A remote attacker can send crafted HTTP packets that force the controller into defect mode, causing denial of service. For sites using these PLCs in production, the business concern is process interruption, not data theft. Exposure is limited to environments with Siemens SIMATIC S7-1200 CPU PLCs on firmware before 4.0, especially where the device HTTP service is reachable from untrusted networks or poorly segmented OT networks. Prioritize affected PLCs that support production, safety-adjacent, or remote operations. There is no sourced evidence of active exploitation, but a remotely triggerable PLC outage can create real operational downtime. Mitigation focus: Identify SIMATIC S7-1200 CPUs running firmware before 4.0.; Upgrade affected PLC firmware to version 4.0 or later where Siemens guidance supports it.; Review Siemens ProductCERT advisory SSA-654382 for product-specific remediation guidance..

Prepared

Jun 14, 2026, 14:32 UTC (UTC+00:00)

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