CVE-2016-9848 in phpMyAdmin
Summary
by MITRE
An issue was discovered in phpMyAdmin. phpinfo (phpinfo.php) shows PHP information including values of HttpOnly cookies. All 4.6.x versions (prior to 4.6.5), 4.4.x versions (prior to 4.4.15.9), and 4.0.x versions (prior to 4.0.10.18) are affected.
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Analysis
by VulDB Data Team • 06/25/2019
The vulnerability identified as CVE-2016-9848 represents a critical information disclosure flaw within phpMyAdmin, a widely used web-based database management tool. This issue specifically affects versions of phpMyAdmin spanning multiple release branches including 4.6.x prior to 4.6.5, 4.4.x prior to 4.4.15.9, and 4.0.x prior to 4.0.10.18. The vulnerability stems from the phpinfo.php script which is designed to display detailed PHP configuration information but inadvertently exposes sensitive cookie values to unauthorized users. This flaw occurs because the script fails to properly sanitize or filter the output of PHP information, allowing attackers to access HttpOnly cookies that should be protected from client-side script access. The exposure of these cookie values creates a significant security risk as they may contain session identifiers or other sensitive authentication tokens that could be exploited by malicious actors. The vulnerability directly relates to CWE-200, which describes the exposure of sensitive information to an unauthorized actor, and falls under the broader category of information disclosure vulnerabilities that can lead to session hijacking and privilege escalation attacks.
The technical implementation of this vulnerability involves the phpinfo.php endpoint which is typically accessible to users with appropriate privileges within the phpMyAdmin interface. When this script executes, it displays comprehensive PHP configuration details including server environment variables, loaded extensions, and most critically, cookie values that are marked as HttpOnly. This behavior violates fundamental security principles where HttpOnly cookies are specifically designed to prevent cross-site scripting attacks by ensuring that client-side scripts cannot access cookie values. The flaw allows attackers to extract session tokens and other sensitive information that should remain protected from client-side access. From an operational perspective, this vulnerability creates a pathway for attackers to potentially hijack user sessions and gain unauthorized access to database management interfaces. The impact is particularly severe because phpMyAdmin is commonly deployed in environments where database administrators have elevated privileges, making the compromise of a session potentially devastating to overall system security. The vulnerability also aligns with ATT&CK technique T1566, which covers credential harvesting through phishing and social engineering, as the exposure of session tokens makes such attacks more effective.
The operational consequences of this vulnerability extend beyond simple information disclosure, as it creates opportunities for attackers to escalate privileges and conduct further reconnaissance within the compromised environment. Since phpMyAdmin typically provides database administrative capabilities, the exposure of session tokens could enable attackers to execute database commands, access sensitive data, or modify database configurations. The vulnerability is particularly concerning in multi-tenant environments or shared hosting scenarios where multiple users may have access to the same phpMyAdmin instance. Organizations using affected versions should immediately implement mitigations including updating to patched versions, implementing proper access controls, and monitoring for unauthorized access attempts. The recommended remediation involves upgrading to phpMyAdmin versions 4.0.10.18, 4.4.15.9, or 4.6.5 and later, which contain patches addressing the improper cookie handling in the phpinfo.php script. Security teams should also consider implementing network segmentation and access controls to limit exposure of phpMyAdmin interfaces to authorized users only. Additional protective measures include regular security audits of web applications, implementation of web application firewalls, and comprehensive monitoring for suspicious access patterns that may indicate exploitation attempts. The vulnerability serves as a reminder of the importance of proper input validation and output sanitization in web applications, particularly when dealing with system information that may contain sensitive data elements that should remain protected from unauthorized access.