CVE-2022-38803 is a vulnerability affecting Zkteco BioTime versions prior to 8.5.3 Build:20200816.447. The issue arises from incorrect access control related to the handling of Leave, Overtime, and Manual log functionalities within the application. Specifically, an authenticated employee can exploit a Cross-Site Scripting (XSS) vulnerability embedded in the PDF generation feature used when exporting data as a PDF document. By injecting malicious scripts into the export process, the attacker can leverage the PDF generator to read local files on the server or system where the application is hosted. This vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation), indicating that user input is not properly sanitized before being processed or rendered. The attack requires the attacker to have valid authentication credentials (an employee account) and involves user interaction (triggering the export to PDF). The vulnerability impacts confidentiality severely, as it allows unauthorized reading of local files, but does not affect integrity or availability directly. The CVSS 3.1 base score is 6.8 (medium severity), with vector AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:N/A:N, indicating network attack vector, low attack complexity, privileges required, user interaction required, scope changed, high confidentiality impact, no integrity or availability impact. No known exploits in the wild have been reported, and no patches are currently linked, suggesting organizations should prioritize mitigation and monitoring. The vulnerability is particularly relevant for organizations using Zkteco BioTime for workforce management and attendance tracking, as unauthorized file access could expose sensitive employee or organizational data.

For European organizations, the exploitation of this vulnerability could lead to significant confidentiality breaches, exposing sensitive employee information, internal documents, or configuration files stored locally on the affected systems. Given that Zkteco BioTime is commonly used in sectors such as manufacturing, healthcare, education, and public administration for time and attendance management, unauthorized access could compromise personal data protected under GDPR, leading to legal and financial repercussions. The ability to read local files could also facilitate further attacks, such as credential harvesting or lateral movement within the network, increasing the risk of broader compromise. Although the vulnerability does not directly affect system integrity or availability, the confidentiality impact alone is substantial. Organizations with large employee bases or those handling sensitive workforce data are at higher risk. Additionally, the requirement for authenticated access limits the threat to insiders or compromised accounts, but insider threats or credential theft scenarios remain plausible. The scope change in the CVSS vector indicates that the vulnerability could impact resources beyond the initially vulnerable component, potentially affecting other parts of the system or network.

1. Upgrade Zkteco BioTime to version 8.5.3 Build:20200816.447 or later once an official patch is released to address this vulnerability. 2. Implement strict input validation and sanitization on all user inputs, especially those involved in PDF generation and export functionalities, to prevent XSS injection. 3. Restrict access to the PDF export feature to only trusted users or roles with a demonstrated need, minimizing the attack surface. 4. Monitor and audit user activities related to exporting data and accessing sensitive logs to detect anomalous behavior indicative of exploitation attempts. 5. Employ network segmentation and least privilege principles to limit the potential impact of compromised employee accounts. 6. Use Web Application Firewalls (WAFs) with custom rules to detect and block malicious payloads targeting the PDF export functionality. 7. Educate employees about the risks of phishing and credential compromise to reduce the likelihood of unauthorized authenticated access. 8. Regularly review and harden server file permissions to prevent unauthorized file reads even if the application is exploited. 9. Conduct penetration testing focused on PDF export and file access features to identify residual vulnerabilities. 10. Prepare incident response plans specifically addressing insider threats and authenticated exploitation scenarios.