CVE-2021-21910 in R-SeeNet
Summary
by MITRE • 12/22/2021
A privilege escalation vulnerability exists in the Windows version of installation for Advantech R-SeeNet Advantech R-SeeNet 2.4.15 (30.07.2021). A specially-crafted file can be replaced in the system to escalate privileges to NT SYSTEM authority. An attacker can provide a malicious file to trigger this vulnerability.
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Analysis
by VulDB Data Team • 12/24/2021
The vulnerability identified as CVE-2021-21910 represents a critical privilege escalation flaw within Advantech R-SeeNet 2.4.15 installation package for Windows systems. This vulnerability specifically targets the installation process of the Advantech R-SeeNet software, which is widely used for remote monitoring and management of industrial equipment. The flaw allows attackers to elevate their privileges to the highest system level authority known as NT SYSTEM, effectively granting them complete control over the affected system. The vulnerability stems from inadequate file handling and permission management during the installation process, creating a window of opportunity for malicious actors to manipulate the system's security posture.
The technical implementation of this privilege escalation occurs through a carefully crafted malicious file that can be strategically placed within the system to replace legitimate installation components. This flaw operates at the file system level where the installation process fails to properly validate or verify the integrity of files being installed, particularly those that are critical to system security. The vulnerability is categorized under CWE-787 as an out-of-bounds write, though more specifically manifests as a privilege escalation through improper access control mechanisms. When an attacker successfully places the malicious file, the installation process executes with elevated privileges, allowing the malicious component to gain system-level access and execute with full administrative capabilities.
From an operational perspective, this vulnerability presents a severe risk to industrial control systems and network infrastructure that rely on Advantech R-SeeNet for monitoring and management. The attack vector is particularly concerning as it requires only the ability to provide a malicious file to the system, which could be achieved through various means including social engineering, supply chain attacks, or by exploiting other initial access points. Once escalated to NT SYSTEM authority, attackers can manipulate system configurations, install backdoors, exfiltrate sensitive data, and potentially disrupt critical operations. The impact extends beyond individual system compromise to potentially affect entire network segments that depend on the compromised R-SeeNet installation for their operational integrity.
Security mitigations for CVE-2021-21910 should prioritize immediate remediation through official vendor patches and updates. Organizations should implement strict file integrity monitoring to detect unauthorized modifications to installation directories and system files. Network segmentation and least privilege access controls can help limit the potential impact of exploitation, while regular security audits should verify the integrity of installed software components. The vulnerability aligns with ATT&CK technique T1068 which covers privilege escalation through local exploits, and T1547 which addresses registry run keys and startup folder modifications. System administrators should also consider implementing application whitelisting policies to prevent unauthorized executables from running, and conduct regular vulnerability assessments to identify similar flaws in other industrial software installations. The remediation process should include thorough verification that all installed components have not been tampered with and that proper access controls are in place to prevent unauthorized modification of critical system files.