CVE-2024-0530 is a medium-severity SQL Injection vulnerability affecting CXBSoft Post-Office version 1.0. The flaw resides in the HTTP POST request handler component, specifically in the /apps/reg_go.php file. The vulnerability is triggered by manipulation of the 'username_reg' parameter, which is not properly sanitized before being used in SQL queries. This improper input validation allows an attacker with low privileges and no user interaction to inject malicious SQL code. The vulnerability can lead to unauthorized access to or modification of the database, potentially compromising confidentiality, integrity, and availability of the affected system's data. The attack vector is remote and requires authentication, but the low attack complexity means exploitation is feasible for an attacker with limited access. The vendor has been contacted but has not responded or issued a patch, and no known exploits have been reported in the wild yet. The CVSS 3.1 score is 5.5 (medium), reflecting the limited scope and required privileges but acknowledging the potential impact on data security.

For European organizations using CXBSoft Post-Office 1.0, this vulnerability poses a risk of data breaches, unauthorized data modification, and potential service disruption. Given that the flaw allows SQL injection via a user registration parameter, attackers could extract sensitive user information, alter records, or corrupt the database, impacting business operations and compliance with data protection regulations such as GDPR. The lack of vendor response and patch availability increases the risk exposure period. Organizations in sectors with high data sensitivity, such as finance, healthcare, and government, could face reputational damage, regulatory penalties, and operational downtime if exploited. The requirement for authentication limits the attack surface but insider threats or compromised credentials could facilitate exploitation. The medium severity suggests a moderate but non-negligible threat level, warranting prompt mitigation especially in environments where CXBSoft Post-Office is critical to communications or workflow.

European organizations should immediately audit their CXBSoft Post-Office installations to confirm version 1.0 usage. As no official patch is available, mitigation should focus on compensating controls: 1) Restrict access to the /apps/reg_go.php endpoint to trusted users and networks using firewall rules or web application firewalls (WAF) with SQL injection detection and blocking capabilities. 2) Implement strict input validation and sanitization at the application or proxy level to filter malicious payloads targeting the 'username_reg' parameter. 3) Monitor logs for unusual database queries or failed login attempts that may indicate exploitation attempts. 4) Enforce strong authentication and credential management to reduce risk of insider or credential-based attacks. 5) Consider isolating the affected service or migrating to alternative solutions until a vendor patch or update is released. 6) Engage with CXBSoft or security communities for updates or unofficial patches. 7) Conduct regular security assessments and penetration tests focusing on SQL injection vectors in the application.