CVE-2018-19016 in EtherNet-IP Web Server Module 1756-EWEB
Summary
by MITRE
Rockwell Automation EtherNet/IP Web Server Modules 1756-EWEB (includes 1756-EWEBK) Version 5.001 and earlier, and CompactLogix 1768-EWEB Version 2.005 and earlier. A remote attacker could send a crafted UDP packet to the SNMP service causing a denial-of-service condition to occur until the affected product is restarted.
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Analysis
by VulDB Data Team • 08/08/2023
The vulnerability identified as CVE-2018-19016 affects Rockwell Automation EtherNet/IP Web Server Modules and CompactLogix controllers that implement SNMP services. This security flaw resides in the network management protocols of industrial control systems, specifically targeting the Simple Network Management Protocol implementation within these devices. The affected products include the 1756-EWEB series and 1756-EWEBK modules running firmware versions 5.001 and earlier, as well as CompactLogix 1768-EWEB controllers with firmware versions 2.005 and earlier. These devices are commonly deployed in industrial environments for networked control and monitoring applications, making them critical components in manufacturing and process control systems.
The technical flaw manifests through a buffer overflow or memory corruption vulnerability within the SNMP service implementation when processing crafted UDP packets. When a remote attacker sends specifically malformed UDP packets to the SNMP service port, the device's memory management fails to properly handle the malformed data, leading to a system crash or unexpected termination of the SNMP service. This vulnerability operates at the network protocol level and requires no authentication to exploit, making it particularly dangerous in industrial settings where network access may be less restricted. The flaw essentially allows an unauthenticated attacker to cause a denial-of-service condition that persists until the affected device is manually restarted or power-cycled.
The operational impact of this vulnerability extends beyond simple service disruption, potentially affecting critical industrial processes that rely on continuous operation of these controllers. In manufacturing environments, the disruption caused by such a denial-of-service condition could lead to production halts, quality control issues, and significant financial losses. The vulnerability affects devices that are often deployed in remote or hard-to-access locations, complicating the remediation process and potentially requiring on-site intervention. Industrial control systems are typically designed for long-term reliability and uptime, making this type of vulnerability particularly concerning as it can compromise the availability of critical control functions. The impact is further exacerbated by the fact that these devices are often part of larger industrial networks where a single compromised device could affect multiple connected systems.
Organizations should implement immediate mitigations including network segmentation to isolate affected devices from general network access, disabling unnecessary SNMP services when not required, and applying firmware updates from Rockwell Automation once available. Network monitoring solutions should be deployed to detect unusual UDP traffic patterns that may indicate exploitation attempts. The vulnerability aligns with CWE-121 and CWE-122 categories related to buffer overflow conditions, and represents a significant risk under ATT&CK framework's TA0043 (Reconnaissance) and TA0040 (Execution) tactics. Security teams should also consider implementing network access controls and firewall rules to restrict UDP traffic to only trusted sources and necessary ports. Regular vulnerability assessments and network scanning should be conducted to identify other potentially affected devices within industrial control system environments, as similar vulnerabilities may exist in other industrial protocols and implementations.