CVE-2016-9865 in phpMyAdmin
Summary
by MITRE
An issue was discovered in phpMyAdmin. Due to a bug in serialized string parsing, it was possible to bypass the protection offered by PMA_safeUnserialize() function. 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 • 10/05/2022
The vulnerability identified as CVE-2016-9865 represents a critical serialization flaw within phpMyAdmin that undermines the application's security mechanisms designed to prevent malicious data manipulation. This issue specifically targets the PMA_safeUnserialize() function which serves as a protective layer against insecure deserialization attacks. The flaw exists in multiple version branches of phpMyAdmin including the 4.6.x series prior to 4.6.5, 4.4.x series prior to 4.4.15.9, and 4.0.x series prior to 4.0.10.18, indicating a widespread impact across the application's release history.
The technical root cause of this vulnerability lies in the improper handling of serialized string parsing within phpMyAdmin's internal security mechanisms. When the application processes serialized data, the flawed implementation allows attackers to manipulate serialized objects in ways that circumvent the intended safety checks. This occurs because the PMA_safeUnserialize() function fails to properly validate or sanitize the serialized data structure, creating an avenue for attackers to inject malicious payloads that would normally be rejected by the security layer. The vulnerability operates at the core of phpMyAdmin's data handling architecture, specifically targeting the serialization and deserialization processes that are fundamental to the application's operation.
The operational impact of CVE-2016-9865 extends beyond simple data corruption or application instability. Attackers who successfully exploit this vulnerability can potentially achieve unauthorized access to database systems, execute arbitrary code, or manipulate sensitive data within the phpMyAdmin environment. The bypass of PMA_safeUnserialize() protection means that attackers can craft serialized objects that contain malicious PHP code or objects that trigger unintended behavior when processed by the application. This type of vulnerability aligns with common attack patterns described in the ATT&CK framework under the technique of "Deserialization of Untrusted Data" and can be classified as CWE-502, which specifically addresses unsafe deserialization vulnerabilities. The impact is particularly severe in environments where phpMyAdmin serves as a database management interface, as it provides attackers with potential access to underlying database systems and sensitive information.
Organizations affected by this vulnerability should immediately implement mitigations including updating to patched versions of phpMyAdmin, specifically versions 4.6.5, 4.4.15.9, and 4.0.10.18 respectively. Additionally, administrators should consider implementing network-level restrictions to limit access to phpMyAdmin interfaces, particularly from untrusted networks. The vulnerability demonstrates the critical importance of proper input validation and serialization handling in web applications, and serves as a reminder of the potential consequences when security functions fail to properly validate data integrity. Security monitoring should be enhanced to detect unusual patterns in serialized data processing, and regular security assessments should be conducted to identify similar vulnerabilities in other applications that rely on similar serialization mechanisms.