CVE-2025-4857 is a Local File Inclusion vulnerability affecting the contrid Newsletters plugin for WordPress in all versions up to and including 4.9.9.9. The vulnerability stems from improper validation of the 'file' parameter, which allows an authenticated attacker with Administrator-level access or higher to perform path traversal attacks (CWE-22). By manipulating this parameter, attackers can include arbitrary files from the server filesystem, including those uploaded as images or other seemingly safe file types, which can contain malicious PHP code. This leads to arbitrary code execution within the context of the web server, enabling attackers to bypass access controls, access sensitive data, and potentially take full control of the affected system. The vulnerability has a CVSS v3.1 score of 7.2, reflecting high severity due to network attack vector, low attack complexity, and high impact on confidentiality, integrity, and availability. Although no known exploits are currently in the wild, the presence of administrator privileges as a prerequisite limits but does not eliminate risk, as compromised admin accounts or insider threats could leverage this flaw. The plugin is widely used in WordPress environments, making this a significant risk for many organizations relying on this CMS and plugin combination.

The impact of CVE-2025-4857 is substantial for organizations using the contrid Newsletters plugin on WordPress. Successful exploitation allows attackers to execute arbitrary PHP code on the web server, which can lead to full system compromise, data exfiltration, and disruption of services. Confidentiality is at risk due to unauthorized access to sensitive files and data. Integrity can be compromised by altering website content or injecting malicious code. Availability may be affected if attackers deploy destructive payloads or ransomware. Since the vulnerability requires administrator-level access, the threat is particularly critical in environments where admin credentials are weak, reused, or otherwise compromised. Organizations with public-facing WordPress sites using this plugin are at risk of targeted attacks, especially if they do not have strong access controls or monitoring in place. The potential for bypassing access controls and executing arbitrary code makes this vulnerability a high priority for remediation.

To mitigate CVE-2025-4857, organizations should immediately update the contrid Newsletters plugin to a patched version once available. Until a patch is released, restrict administrator access to trusted personnel only and enforce strong, unique passwords combined with multi-factor authentication to reduce the risk of credential compromise. Implement strict input validation and web application firewall (WAF) rules to detect and block path traversal attempts targeting the 'file' parameter. Regularly audit and monitor logs for suspicious file inclusion activities or unexpected PHP execution patterns. Disable or restrict file upload capabilities if not essential, and ensure uploaded files are validated and stored outside the web root to prevent direct execution. Employ the principle of least privilege for WordPress roles to minimize the number of users with administrator access. Additionally, conduct regular security assessments and penetration testing focused on plugin vulnerabilities to identify and remediate similar issues proactively.