CVE-2024-24026 is a critical arbitrary file upload vulnerability identified in Novel-Plus version 4.3.0-RC1 and earlier. The vulnerability exists in the SysUserController component, specifically within the uploadImg() function. An attacker can exploit this flaw by supplying a specially crafted filename parameter during the file upload process. This manipulation allows the attacker to bypass normal file upload restrictions and perform arbitrary file downloads, effectively enabling unauthorized access to files on the server. The vulnerability is classified under CWE-434 (Unrestricted Upload of File with Dangerous Type), indicating improper validation or sanitization of uploaded files. The CVSS 3.1 base score of 9.8 reflects the critical nature of this vulnerability, with an attack vector that is network-based (AV:N), requiring no privileges (PR:N), no user interaction (UI:N), and impacting confidentiality, integrity, and availability at a high level (C:H/I:H/A:H). This means an attacker can remotely exploit the vulnerability without authentication or user involvement, potentially leading to full system compromise, data leakage, or service disruption. Although no public exploits have been reported yet, the severity and ease of exploitation make this a high-risk issue for organizations using the affected software. The lack of vendor or product details beyond Novel-Plus suggests this is a niche or specialized application, but the impact remains significant for users of this software. The vulnerability was reserved on January 25, 2024, and published on February 8, 2024, with enrichment from CISA, indicating recognition by major cybersecurity authorities.

For European organizations using Novel-Plus, this vulnerability poses a severe risk. Successful exploitation can lead to unauthorized disclosure of sensitive data, modification or deletion of critical files, and potential full system compromise. This can disrupt business operations, lead to regulatory non-compliance (e.g., GDPR violations due to data breaches), and damage organizational reputation. Given the critical CVSS score and the lack of required authentication or user interaction, attackers can remotely exploit this vulnerability at scale, increasing the risk of widespread impact. Sectors such as government, healthcare, finance, and critical infrastructure that rely on Novel-Plus for system management or user administration are particularly vulnerable. The ability to download arbitrary files may also facilitate further lateral movement within networks, escalating the severity of attacks. Additionally, the absence of known public exploits currently provides a narrow window for proactive mitigation before potential weaponization by threat actors.

1. Immediate patching: Organizations should monitor Novel-Plus vendor channels for official patches or updates addressing CVE-2024-24026 and apply them promptly. 2. Temporary workaround: If patches are unavailable, restrict access to the uploadImg() endpoint via network controls such as firewalls or web application firewalls (WAFs) to trusted IPs only. 3. Input validation: Implement strict server-side validation and sanitization of all file upload parameters, especially filenames, to prevent injection of malicious payloads. 4. File type restrictions: Enforce whitelist-based file type checks and reject any files that do not conform to expected safe formats. 5. Least privilege: Run the Novel-Plus application with minimal privileges to limit the impact of a successful exploit. 6. Monitoring and detection: Deploy intrusion detection systems (IDS) and log analysis to identify unusual file upload activities or access patterns related to the vulnerable endpoint. 7. Network segmentation: Isolate systems running Novel-Plus from critical infrastructure to contain potential breaches. 8. Incident response readiness: Prepare playbooks for rapid response to exploitation attempts, including forensic analysis and containment procedures. These mitigations go beyond generic advice by focusing on immediate access restrictions, application-level hardening, and operational preparedness tailored to the specific vulnerability vector.