CVE-2016-5734 in phpMyAdmin
Summary
by MITRE
phpMyAdmin 4.0.x before 4.0.10.16, 4.4.x before 4.4.15.7, and 4.6.x before 4.6.3 does not properly choose delimiters to prevent use of the preg_replace e (aka eval) modifier, which might allow remote attackers to execute arbitrary PHP code via a crafted string, as demonstrated by the table search-and-replace implementation.
If you want to get the best quality for vulnerability data then you always have to consider VulDB.
Analysis
by VulDB Data Team • 02/01/2025
The vulnerability identified as CVE-2016-5734 represents a critical security flaw in phpMyAdmin versions prior to specific patched releases, affecting the 4.0.x, 4.4.x, and 4.6.x series. This issue stems from improper delimiter selection during regular expression processing, specifically within the preg_replace function's eval modifier implementation. The flaw allows remote attackers to inject malicious code through crafted input strings, particularly when utilizing table search-and-replace functionality. The vulnerability operates at the core of phpMyAdmin's text processing capabilities, where user-provided data is processed through regular expression functions without adequate sanitization. This represents a classic code injection vulnerability that can be exploited across multiple versions of the popular database administration tool, affecting installations that have not been updated to the patched releases.
The technical execution of this vulnerability occurs when phpMyAdmin processes user input through the preg_replace function with the eval modifier enabled. When an attacker crafts a malicious string that includes the preg_replace e modifier, the system fails to properly sanitize or escape the input before processing. This flaw specifically manifests in the table search-and-replace implementation where user-entered patterns and replacements are processed without proper validation of delimiters. The vulnerability is categorized under CWE-94, which describes "Improper Control of Generation of Code ('Code Injection')" and aligns with ATT&CK technique T1059.007 for "Command and Scripting Interpreter: Python" and broader code injection patterns. The improper handling of regular expression delimiters allows attackers to inject arbitrary PHP code that executes within the web server context, potentially leading to complete system compromise.
The operational impact of CVE-2016-5734 is severe and far-reaching, as it enables remote code execution on vulnerable phpMyAdmin installations. Attackers can leverage this vulnerability to execute arbitrary commands on the target system, potentially gaining full administrative control over the database server and underlying web infrastructure. The vulnerability affects not just individual database instances but can compromise entire web applications that rely on phpMyAdmin for database management. Organizations using unpatched versions face significant risk of data breaches, unauthorized access to sensitive information, and potential lateral movement within their network infrastructure. The impact extends beyond immediate code execution to include potential privilege escalation, data exfiltration, and system-wide compromise. The vulnerability's presence in widely used phpMyAdmin versions means that numerous web applications and database management systems across various industries are potentially exposed to this attack vector.
Mitigation strategies for CVE-2016-5734 require immediate action to update phpMyAdmin installations to the patched versions 4.0.10.16, 4.4.15.7, and 4.6.3, which address the delimiter selection issue and prevent the exploitation of the preg_replace e modifier. Organizations should implement comprehensive patch management procedures to ensure all phpMyAdmin instances are updated promptly. Additional protective measures include implementing web application firewalls to monitor and filter suspicious regular expression patterns, restricting direct internet access to phpMyAdmin installations, and implementing proper input validation at multiple layers of the application. Security teams should also consider disabling unnecessary phpMyAdmin features, particularly those involving regular expression processing, and establish monitoring for unusual search-and-replace operations. The vulnerability serves as a reminder of the critical importance of proper input sanitization and delimiter handling in regular expression processing, emphasizing the need for robust security practices in web application development and maintenance.