CVE-2016-20032 in ZKAccess Security System
Summary
by MITRE • 03/16/2026
ZKTeco ZKAccess Security System 5.3.1 contains a stored cross-site scripting vulnerability that allows attackers to execute arbitrary HTML and script code by injecting malicious payloads through the 'holiday_name' and 'memo' POST parameters. Attackers can submit crafted requests with script code in these parameters to compromise user browser sessions and steal sensitive information.
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Analysis
by VulDB Data Team • 03/16/2026
The vulnerability identified as CVE-2016-20032 resides within the ZKTeco ZKAccess Security System version 5.3.1, a widely deployed access control solution used in enterprise and industrial environments. This system manages employee access permissions and security protocols across various facilities, making it a critical component in organizational cybersecurity infrastructure. The flaw manifests as a stored cross-site scripting vulnerability that fundamentally compromises the integrity of user sessions and data protection mechanisms. The vulnerability specifically affects the system's handling of user input through two distinct POST parameters: 'holiday_name' and 'memo', which are utilized for managing holiday schedules and administrative notes respectively.
The technical implementation of this vulnerability stems from inadequate input validation and output encoding within the web application interface of the ZKAccess system. When administrators or users submit data through these parameters, the system fails to properly sanitize or escape the input before storing it in the database and subsequently rendering it in web pages. This allows attackers to inject malicious HTML and JavaScript code directly into the application's data storage layer. The stored nature of this vulnerability means that the malicious payloads persist in the system's database and are executed whenever legitimate users view the affected pages, creating a persistent threat vector that can compromise multiple user sessions over time.
The operational impact of this vulnerability extends beyond simple script execution, creating significant risks for organizations relying on ZKTeco systems for security management. Attackers can leverage this vulnerability to hijack user sessions, steal authentication tokens, and potentially escalate privileges within the access control environment. The stolen session data could enable unauthorized access to restricted areas, manipulation of access schedules, and modification of security policies. Additionally, the vulnerability creates opportunities for data exfiltration and can serve as a foothold for further attacks within the network infrastructure. Organizations using this system face potential compliance violations and regulatory penalties due to the exposure of sensitive access control information.
Mitigation strategies for CVE-2016-20032 should prioritize immediate system updates and patches provided by ZKTeco to address the input validation flaws. Organizations must implement comprehensive input sanitization measures, including proper HTML escaping and content security policy enforcement, to prevent malicious code injection. Network segmentation and monitoring of web application traffic can help detect anomalous requests targeting these vulnerable parameters. Security teams should also conduct thorough vulnerability assessments of all web-based components within the access control infrastructure, applying the principle of least privilege to limit the impact of potential compromises. This vulnerability aligns with CWE-79, which addresses cross-site scripting flaws, and represents a significant concern for organizations following ATT&CK framework's TA0001 Initial Access and TA0003 Persistence tactics, as it enables attackers to establish long-term access through compromised user sessions.