CVE-2025-28357 is a vulnerability identified in Neto CMS versions 6.313.0 through 6.314.0, characterized as a CRLF (Carriage Return Line Feed) injection flaw. CRLF injection vulnerabilities occur when an attacker can inject CRLF characters into input fields that are subsequently included in HTTP headers or other protocol elements. This can allow attackers to manipulate HTTP responses, potentially leading to HTTP response splitting, web cache poisoning, cross-site scripting (XSS), or in this case, arbitrary code execution. The vulnerability arises because the CMS does not properly sanitize or validate crafted HTTP requests containing CRLF sequences, enabling attackers to inject malicious payloads. The arbitrary code execution vector suggests that the injection can be leveraged to execute commands on the server hosting the CMS, which significantly elevates the threat level. Although no CVSS score has been assigned yet and no known exploits are reported in the wild, the vulnerability's nature implies a critical security risk. The absence of patch links indicates that a fix may not yet be publicly available, increasing the urgency for organizations using these versions to monitor for updates or apply mitigations. The vulnerability was reserved in March 2025 and published in October 2025, indicating recent discovery and disclosure. Given that Neto CMS is a content management system, it is likely used by organizations to manage websites and web applications, making the potential impact broad if exploited.

For European organizations, the impact of CVE-2025-28357 could be severe. Successful exploitation could lead to full compromise of web servers running vulnerable versions of Neto CMS, resulting in unauthorized access to sensitive data, defacement of websites, disruption of services, or use of compromised servers as a foothold for further attacks within corporate networks. Confidentiality could be breached if attackers access stored data or intercept user sessions. Integrity is at risk due to possible content manipulation or injection of malicious scripts affecting end users. Availability could be impacted if attackers disrupt services or cause denial-of-service conditions. Given the arbitrary code execution capability, attackers could deploy ransomware, steal credentials, or pivot to other internal systems. European organizations in sectors such as e-commerce, government, education, and media that rely on Neto CMS for their web presence are particularly at risk. Additionally, compliance with GDPR and other data protection regulations means that exploitation could lead to regulatory penalties and reputational damage.

Immediate mitigation steps include: 1) Identifying and inventorying all instances of Neto CMS in use within the organization, specifically versions 6.313.0 through 6.314.0. 2) Monitoring official Neto CMS channels and security advisories for patches or updates addressing CVE-2025-28357 and applying them promptly once available. 3) Implementing Web Application Firewalls (WAFs) with custom rules to detect and block HTTP requests containing suspicious CRLF sequences or malformed headers that could exploit this vulnerability. 4) Employing strict input validation and sanitization on all HTTP headers and user inputs at the application and network layers to prevent injection attacks. 5) Conducting regular security assessments and penetration testing focused on HTTP header injection and code execution vectors. 6) Restricting permissions of the web server process to minimize the impact of potential code execution. 7) Monitoring logs for unusual HTTP requests or server behavior indicative of exploitation attempts. 8) Considering temporary mitigation by isolating vulnerable CMS instances or limiting their exposure until patches are applied.