CVE-2023-53907 is a path traversal vulnerability affecting the Backup Plugin of Bludit CMS versions before 3.13.1. The flaw arises from improper validation and limitation of pathname inputs in the plugin's file download functionality. Authenticated users with at least low privileges can manipulate the file path parameters to traverse directories and access files outside the intended restricted backup directory. This vulnerability does not require user interaction beyond authentication and can be exploited remotely over the network. The impact is primarily on confidentiality, as attackers can read arbitrary files, including sensitive system files, configuration files, or other protected data stored on the server. The vulnerability has a CVSS 4.0 base score of 7.1, indicating high severity, with attack vector network (AV:N), low attack complexity (AC:L), no privileges required beyond authentication (PR:L), no user interaction (UI:N), and high impact on confidentiality (VC:H). No known exploits have been reported in the wild yet, but the vulnerability poses a significant risk to affected systems. The vulnerability affects Bludit CMS installations using the Backup Plugin prior to version 3.13.1, which should be updated to remediate the issue. Since Bludit is a lightweight flat-file CMS popular among small to medium websites, the exposure could be significant for organizations relying on it for content management without additional security controls.

For European organizations, this vulnerability could lead to unauthorized disclosure of sensitive information such as system credentials, configuration files, or proprietary data stored on web servers running vulnerable Bludit CMS instances. This can facilitate further attacks like privilege escalation, lateral movement, or data breaches. Small and medium enterprises, educational institutions, and local government websites using Bludit are particularly at risk due to potentially limited security monitoring and patch management. The breach of confidentiality could result in regulatory non-compliance under GDPR, leading to financial penalties and reputational damage. Additionally, attackers could leverage exposed information to compromise other internal systems or launch targeted attacks. The vulnerability's exploitation requires only authenticated access, which may be easier to obtain via phishing or credential stuffing, increasing the risk. Although no active exploitation is reported, the high severity and ease of exploitation warrant immediate attention to prevent potential incidents.

European organizations should immediately update the Bludit CMS Backup Plugin to version 3.13.1 or later, where the vulnerability is fixed. If immediate patching is not feasible, restrict access to the Backup Plugin functionality to trusted administrators only, using web application firewalls (WAFs) or access control lists (ACLs). Implement strict authentication and authorization controls to limit user privileges and monitor for unusual file download requests indicative of path traversal attempts. Employ logging and alerting on file access patterns to detect exploitation attempts early. Conduct regular security audits of CMS plugins and configurations to identify and remediate similar vulnerabilities. Additionally, consider isolating CMS instances in segmented network zones to limit the impact of potential breaches. Educate users on secure credential management to reduce the risk of unauthorized authenticated access. Finally, maintain up-to-date backups and incident response plans to quickly recover from any compromise.