CVE-2025-51655 is a SQL injection vulnerability identified in SemCms version 5.0, specifically exploitable via the 'pid' parameter in the SEMCMS_Quanxian.php script. SQL injection vulnerabilities occur when untrusted input is improperly sanitized and directly incorporated into SQL queries, allowing an attacker to manipulate the database query logic. In this case, the 'pid' parameter likely accepts user input that is concatenated into a SQL statement without adequate validation or parameterization. Exploiting this vulnerability could enable an attacker to execute arbitrary SQL commands against the backend database, potentially leading to unauthorized data disclosure, data modification, or even complete compromise of the database server. The vulnerability does not currently have a CVSS score assigned, and no known exploits are reported in the wild as of the publication date (July 14, 2025). The lack of patch links suggests that a fix may not yet be publicly available or disclosed. Given that SemCms is a content management system, the affected component SEMCMS_Quanxian.php likely relates to permission or access control management, which could amplify the impact if exploited. The vulnerability's exploitation requires sending crafted requests to the vulnerable parameter, which may not require authentication depending on the CMS configuration, increasing the attack surface. Overall, this vulnerability represents a significant risk to the confidentiality, integrity, and availability of data managed by SemCms installations running version 5.0.

For European organizations using SemCms v5.0, this SQL injection vulnerability poses a serious threat. Successful exploitation could lead to unauthorized access to sensitive data, including personal data protected under GDPR, potentially resulting in data breaches with legal and financial repercussions. Integrity of organizational data could be compromised, affecting business operations and trustworthiness of information. Availability could also be impacted if attackers execute destructive SQL commands or cause database corruption. Since SemCms is a CMS, websites or internal portals relying on it could be defaced or taken offline, disrupting services. The absence of known exploits currently provides a window for proactive mitigation, but the public disclosure increases the risk of future exploitation attempts. European organizations must consider the regulatory implications of data breaches and the reputational damage associated with compromised web assets. The impact is heightened for sectors with critical data or services, such as government, healthcare, finance, and e-commerce.

To mitigate this vulnerability, European organizations should first identify all instances of SemCms v5.0 in their environment. Since no official patch is currently linked, organizations should implement immediate compensating controls: 1) Apply strict input validation and sanitization on the 'pid' parameter at the web application firewall (WAF) or reverse proxy level to block malicious SQL payloads. 2) Employ parameterized queries or prepared statements in the application code if source code access and modification are possible. 3) Restrict database user privileges to the minimum necessary to limit the impact of any SQL injection. 4) Monitor web server and database logs for suspicious activities targeting the 'pid' parameter or unusual SQL errors. 5) Consider temporarily disabling or restricting access to the SEMCMS_Quanxian.php script if feasible. 6) Engage with the SemCms vendor or community to obtain or request a security patch and apply it promptly once available. 7) Conduct security awareness training for developers and administrators on secure coding and vulnerability management. These steps, combined with regular vulnerability scanning and penetration testing, will reduce the risk until a formal patch is released.