CVE-2020-11496 in SPRECON-E
Summary
by MITRE • 10/20/2020
Sprecher SPRECON-E firmware prior to 8.64b might allow local attackers with access to engineering data to insert arbitrary code. This firmware lacks the validation of the input values on the device side, which is provided by the engineering software during parameterization. Attackers with access to local configuration files can therefore insert malicious commands that are executed after compiling them to valid parameter files (“PDLs”), transferring them to the device, and restarting the device.
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Analysis
by VulDB Data Team • 11/21/2020
The vulnerability identified as CVE-2020-11496 affects the Sprecher SPRECON-E firmware versions prior to 8.64b, presenting a critical security risk that stems from insufficient input validation mechanisms within the device's firmware architecture. This flaw specifically targets the parameterization process where engineering data is typically validated by specialized software before being transferred to the device. The vulnerability creates an attack surface where local adversaries with access to engineering configuration files can manipulate the system through deliberate code injection, bypassing normal security controls that should prevent unauthorized modifications. The absence of device-side validation means that any malicious commands embedded within parameter files are executed without proper verification, fundamentally undermining the integrity of the system's configuration process.
The technical implementation of this vulnerability lies in the firmware's failure to validate input parameters received during the parameterization phase, which is a direct violation of security best practices outlined in CWE-20, "Improper Input Validation." The attack vector requires local access to engineering data and configuration files, making it particularly dangerous in environments where physical access controls are insufficient or where insider threats exist. The process involves three distinct stages: crafting malicious commands within engineering files, compiling these into valid parameter data files known as PDLs, transferring the compromised files to the target device, and finally restarting the device to execute the injected code. This multi-step process demonstrates a sophisticated attack methodology that leverages the trust relationship between engineering software and the device firmware, exploiting the lack of defensive mechanisms at the device level.
The operational impact of CVE-2020-11496 extends beyond simple code execution, as it represents a complete compromise of the device's integrity and potentially the broader network it connects to. Once malicious code is executed, attackers can establish persistent access, modify device behavior, or use the compromised system as a foothold for further network infiltration. The vulnerability particularly affects industrial control systems where the SPRECON-E devices are commonly deployed, creating risks for critical infrastructure operations. From an attack perspective, this vulnerability aligns with techniques described in the MITRE ATT&CK framework under the T1059.001 tactic for Command and Scripting Interpreter, where adversaries leverage system interfaces to execute malicious code. The attack chain demonstrates how insufficient validation at the device level can enable privilege escalation and persistent access, making it particularly dangerous in operational technology environments where system reliability and security are paramount.
Organizations affected by this vulnerability should prioritize immediate firmware updates to version 8.64b or later, which implements the necessary input validation controls to prevent unauthorized code injection. Additionally, implementing strict access controls for engineering data and configuration files can significantly reduce the attack surface, as the vulnerability requires local access to be exploited. Network segmentation and monitoring of device communications can provide early detection of potential compromise attempts, while regular security assessments should verify that no unauthorized modifications have occurred. The remediation approach should also include comprehensive security awareness training for personnel who handle engineering data, as the vulnerability can be exploited through insider threats or compromised credentials. Implementing proper change management procedures for firmware updates and configuration modifications will further strengthen the overall security posture, addressing both the immediate vulnerability and broader security gaps that could be exploited by similar attacks.