CVE-2017-20038 in Access Controller
Summary
by MITRE • 06/11/2022
A vulnerability was found in SICUNET Access Controller 0.32-05z and classified as critical. Affected by this issue is some unknown functionality of the file card_scan_decoder.php. The manipulation of the argument No/door leads to privilege escalation. The attack may be launched remotely.
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Analysis
by VulDB Data Team • 11/22/2022
The vulnerability identified as CVE-2017-20038 represents a critical privilege escalation flaw within the SICUNET Access Controller version 0.32-05z software ecosystem. This security weakness resides in the card_scan_decoder.php file, which serves as a critical component for processing access control card data within the system. The vulnerability specifically manifests when an attacker manipulates the No/door argument parameter, allowing unauthorized elevation of privileges within the access control infrastructure. The attack vector is particularly concerning as it can be executed remotely, eliminating the need for physical access or local system compromise. This remote exploit capability significantly broadens the threat surface and increases the potential impact of the vulnerability.
The technical exploitation of this flaw involves manipulating the No/door argument within the card_scan_decoder.php functionality to bypass authentication mechanisms and gain elevated privileges within the access control system. This type of vulnerability falls under the CWE-264 category of permissions, privileges, and access control weaknesses, specifically representing a privilege escalation vulnerability that allows attackers to perform actions beyond their authorized scope. The vulnerability's classification as critical indicates the severe implications for system security, as unauthorized users could potentially gain administrative access to the access control infrastructure, compromising the entire security framework of the protected facilities.
The operational impact of this vulnerability extends far beyond simple access control breaches, as it fundamentally undermines the integrity of the entire access management system. An attacker who successfully exploits this vulnerability could potentially grant themselves unlimited access to restricted areas, modify access permissions for other users, or even disable security features entirely. This compromise directly affects the CIA triad, particularly compromising both confidentiality and integrity aspects of the system. The remote exploitation capability means that attackers do not require physical presence or network access to the target system, making the vulnerability particularly dangerous for organizations relying on remote access capabilities for their security infrastructure management.
Mitigation strategies for CVE-2017-20038 should prioritize immediate patching of the SICUNET Access Controller software to the latest available version that addresses this specific privilege escalation vulnerability. Organizations should implement network segmentation to limit access to the affected system and deploy intrusion detection systems to monitor for suspicious parameter manipulation attempts. The principle of least privilege should be enforced by restricting access to the card_scan_decoder.php file and related functionality to only authorized personnel. Additionally, security monitoring should include logging and alerting mechanisms for unusual parameter values being passed to the door access control functions, as this would help detect exploitation attempts. Organizations should also consider implementing multi-factor authentication for administrative access to the access control system and regularly audit access logs to identify any unauthorized privilege escalation attempts. The vulnerability's characteristics align with ATT&CK technique T1068 which involves privilege escalation through exploitation of system vulnerabilities, making it essential for security teams to incorporate this threat into their incident response procedures and threat hunting activities.